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• Career Development

Top 40 Front End Developer Interview Questions and Answers [2024]

You're about to embark on the next step of your career as a front-end developer . But how do you get started?

First, note that a front-end developer can mean many things. When we normally say "front-end," we mean web applications. But it can also mean iOS, Android, Microsoft, osX, or even Linux applications. Front-end developers focus primarily on design and sometimes, IDEs . Know what type of front-end role you're going for before you start studying — because there will be technical questions involved.

But before we dive into our front end developer interview questions, let's explore what it means to be a front-end developer and what people are likely to ask.

• Front-End Developer Interviews: What Can You Expect?

When interviewing for a front-end developer role, expect questions about your skills and experience with HTML , CSS , and JavaScript . An interviewer may also ask questions about your experience with specific frameworks or libraries, such as React or Angular .

Talk about your process for building web applications, including how you structure your code and handle cross-browser compatibility issues. 

In general, the first interview will qualify you with basic questions. The second interview will be more of a "meet and greet" to determine whether you fit the team and company culture. 

And the third (and hopefully final) interview may either be a coding test (more common for full-stack or back-end developers) or a panel interview (with people who will work with you).

Now, let's get started with those front-end interview questions.

• Basic Front End Interview Questions

You've just started your career. We’ll start with entry-level front end developer interview questions for beginner roles. 

These front end engineering interview questions aim to confirm you know the basics of development and design.

1. What is a CDN?

A content delivery network (CDN) is a system for delivering content to users based on geographic location. CDNs can deliver websites, software applications, and other types of digital content.

2. What is AJAX?

AJAX is a web development technique for creating asynchronous web applications. AJAX allows you to create dynamic, responsive web applications that can be updated without reloading the page.

3. What are the differences between HTML and XHTML?

HTML is the standard markup language for creating web pages. XHTML is a stricter and more well-defined version of HTML. It's frequently used for formatting more complex documents within a stated taxonomy.

XHTML code:

4. What is responsive design?

Responsive design is a web development technique that creates websites compatible with multiple devices with different screen sizes. Responsive websites are designed to look good on both desktop and mobile devices.

5. What are the different types of CSS selectors?

CSS selectors are used to select elements in an HTML document. There are several types of CSS selectors, including class selectors, ID selectors, and attribute selectors.

6. What is a pseudo-class?

A pseudo-class is a selector that styles an element based on its state. For example, the :hover pseudo-class styles an element when the user hovers over it with their mouse but does nothing when they don't.

7. What is a CSS reset?

A CSS reset is a set of rules applied to all browsers to normalize the default styling of HTML elements. It’s particularly useful when stripping the formatting of HTML elements.

8. What is a CSS grid system?

A CSS grid system is a set of rules that can be used to create a responsive layout. There are many different grid systems available, but the most popular one is Bootstrap. Bootstrap makes it easier to create layouts that react predictably without having to reinvent the wheel.

9. What is a CSS preprocessor?

A CSS preprocessor is a tool that allows you to write CSS in a more concise and structured manner. The most popular CSS preprocessors are Less and Sass. They aren't very useful for small projects but become exponentially more powerful as a project grows.

10. What are the benefits of using a CSS preprocessor?

There are several benefits of using a CSS preprocessor, such as writing code in a more structured and concise manner, reducing the amount of code that needs to be written, and making it easier to maintain and update code. More importantly, it makes it easier to manage a project among large numbers of devs.

11. What is Bootstrap?

Bootstrap is a popular CSS framework providing a set of rules for creating responsive layouts.

12. What are the benefits of using bootstrap?

Some benefits of using bootstrap include reducing required written code, having a consistent framework across multiple projects, and easier creation of responsive layouts.

13. What is a task runner?

Task runners are tools that help automate common tasks in the development process, such as minification, compilation, linting, etc. Some of the most popular task runners are Gulp and Grunt.

14. What are the benefits of using a task runner?

The benefits of using a task runner include reducing the amount of time spent on repetitive tasks, automating tedious and error-prone tasks, and making it easier to manage the development process.

And also expect these front end developer interview questions, which will have unique answers based on your own personal experiences...

15. What made you become a front-end developer?

16. what is your favorite thing about being a front-end developer.

• Intermediate Front-End Engineer Interview Questions

You've probably been a front-end developer for at least a few years, which is forever in development time. It's time to prove your knowledge. 

Interestingly, these questions are usually less technical. Instead, interviewers want to know broader information about how you solve problems. These frontend developer interview questions reflect a different type of frontend developer interview, focused more on experience than skills.

17. What type of front-end development do you specialize in?

A lot of front-end developers are jacks-of-all-trades. But your interviewer wants to know where most of your experience lies. Do you have more experience with Angular than React? Do you prefer vanilla JavaScript over using a framework?

18. What is your favorite CSS framework?

Do you like the grid system of Bootstrap? The simplicity of Foundation? Most interviewers will be somewhat familiar with the most popular systems, but if you can surprise them (and justify your answer), you may gain points. 

19. How would you optimize a website's performance?

This is a broad question with many potential answers. 

First, you should make sure that your code is minified and compressed. This reduces the size of your files, which makes them faster to download. 

Second, you should use caching wherever possible. This stores frequently used files locally, so they don't need to be downloaded every time a user visits your site. But don’t overdo it, or your site won’t be as dynamic as you want — it won’t update as reliably.

Finally, you should use a content delivery network (CDN). This distributes your files across multiple servers, so users can download them from their respective locations. 

20. What is your favorite front-end development tool?

A front-end development tool is any software that helps develop a website or web application. Some of the most popular front-end development tools are code editors and IDEs , task runners, and CSS preprocessors. Play it safe by mentioning something like Sass or Git, or get more in the weeds with a specialized tool. You can even suggest that your favorite tool is a color picker or a UI tester.

21. How would you go about debugging a website?

As with speeding up a website, debugging a website is broad. But what they're really asking is for the general steps you might take. Some of the most common methods include using the browser’s developer tools, using an automated quality assurance suite, debugging the code line-by-line, or using the " rubber duck " method of debugging.

22. What are some common issues that you have faced with cross-browser compatibility?

Some of the most common issues with cross-browser compatibility are different browsers rendering CSS differently, different browsers supporting different HTML and CSS features, and different browsers having different levels of support for standards. This is particularly difficult as many browsers differ depending on the platform, and the platform differs so widely; someone can open Chrome OS on a smart fridge today.

23. What are some of the common front-end development challenges that you have faced?

Some of the most common front-end development challenges include cross-browser compatibility issues, dealing with legacy code, and optimizing website performance. Another issue developers frequently run into (but unfortunately less frequently address) is the ability to make their code ADA compliant.

Also be prepared for these personal front end developer interview questions...

24. What blogs do you follow when it comes to front-end development?

25. what websites are your favorite, in terms of design and development.

• Advanced Front End Developer Questions

Once you have five or six years under your belt, interviewers will rarely ask you complex questions about technology, design, development, or even user experience. Instead, front end developer interview questions and answers for experienced applicants tend to be more focused on your career and your successes. Prepare for these challenging front end web developer interview questions.

26. Discuss the biggest achievement of your career.

Be ready to discuss a time when you made a significant impact on a project. This is your opportunity to really sell yourself, so make sure you have a great story to tell. If you can, try to connect your achievement to the company's values or mission statement. Don't be afraid to highlight how a team member or manager helped you. This shows you're a team player.

27. Discuss the biggest challenge of your career.

This is not the time to discuss a personal challenge, like overcoming your fear of public speaking. Instead, focus on a professional challenge that you faced and overcame, such as developing for a defunct system, or encountering a particular UI/UX challenge. Talk about what the problem was, how you tackled it, and what the result was. As with the previous question, try to connect your story to the company's values or mission

28. What was your last project? How did it go?

This is a great opportunity to talk about something you're passionate about. If your last project was particularly challenging or successful, mention it. Be specific about the technologies you used and any unique ways you used them.

29. How do you effectively manage your time?

This is an important question for any developer, as work can be varied and unpredictable. Talk about the tools you use to manage your time (such as a Pomodoro timer) and how you use them. You might also discuss how you prioritize your tasks and deal with unexpected interruptions.

30. What do you do when you get stuck?

No one likes being stuck, but it's a fact of life for any programmer. Talk about methods you use to get unstuck, such as asking for help, doing research, or taking a break. Also, mention how you prevent yourself from getting stuck in the first place, such as research in advance and making sure you don't stretch the project's scope.

31. What do you do when you get something wrong?

Everyone makes mistakes. The important thing is how you react when you make a mistake. Talk about the steps you take to fix mistakes, such as undoing your changes or writing tests. Also, mention how you prevent yourself from making the same mistake twice, such as keeping better documentation.

• Technical Front-End Developer Questions

Apart from regular entry-level front-end developer questions, you're likely to run into some technical questions about HTML, CSS, and JavaScript.

HTML Front-End Developer Questions

Realistically, every front-end developer should know HTML, even if you're developing for iOS or Android. 

32. What are the differences between HTML5 and HTML4?

HTML5 , the latest version of HTML, includes several new elements and attributes. It also supports audio and video playback and introduces support for local storage.

33. How would you create a custom error page?

A custom error page is a page that is displayed when an error occurs. To create a custom error page, you would first need to create a file called "error.php" or "error.html." Then, you would need to edit the .htaccess file to point to the custom error page.

34. How do you use media queries to optimize for different screen sizes?

Media queries are a CSS3 feature that allows you to apply different styles based on the screen’s width. To use media queries, you would first need to include a viewport meta tag in your HTML. Then, you would need to write your CSS using media queries -- but integrating it into the HTML is important, too.

JavaScript Front-End Developer Questions

If you need to master any programming language for impeccable web or mobile development: it’s JavaScript . 

35. What is the difference between == and ===?

== checks for value equality, while === checks for both value and type equality.

36. What is the difference between an anonymous function and a named function?

A named function can be referenced in the future from anywhere in the code, whereas an anonymous function cannot — although it will run when it occurs in-line.

37. What is an event loop?

An event loop is the foundation of real-time JavaScript response. It runs at intervals to test for an event. You will need to initiate event loops to scan for user behaviors like clicks.

CSS Front-End Developer Questions

CSS and HTML are so frequently used together that they are generally learned together and very well integrated. But you should still know where CSS ends and HTML begins. Learn more about CSS to kickstart your development career.

38. What are the differences between inline, embedded, and external stylesheets?

Inline styles are written as a part of the code (<div style=”background-color: blue”>), embedded styles are style sheets embedded in the header of the page, and external style sheets are linked within the header of the page.

39. How do you create a responsive layout?

You can create a responsive layout by using a framework like Bootstrap. Alternatively, you will need to manually detect the screen’s size and make changes. Responsive layout best practices include creating a “fail-proof” system that collapses elements if they are too small to be viewed.

40. How do you use animation and transitions?

Most animations and transitions are brought into CSS through JavaScript; another way in which CSS, JavaScript, and HTML are so entwined. You might name an element in CSS and set its parameters with CSS only to process an animation with JavaScript. There are some built-in animations and transitions in CSS, but they tend to be fairly rudimentary.

• Tips and Tricks for Front End Developer Interview Questions

A front-end developer interview can be stress-free, to a certain extent. The career is growing by leaps and bounds; don't try to prove yourself too much. Walk in with a clean portfolio and prepare with test questions and answers.

• Do your research. Before the interview, make sure to do your research on the company and the position you are applying for. This will help you prepare for questions and show the interviewer that you’re motivated and have a genuine interest in the role.
• Practice, practice, practice. Whether it’s doing a mock interview with a friend or family member, or just going over common questions in your head, practicing beforehand will help you feel more confident and less nervous during the actual interview.
• Build your portfolio. If you're fairly new to the industry or making a switch, build a portfolio with the top sites that you've worked on.
• Know where you are in the pipeline. Initial interviews are just "touch-base" interviews. You should slowly get to know your interview team and the position, and then dig more into your technical skills.
• Be personable. At the end of the day, the interviewer wants to get to know you as a person. The best way to be genuine is to briefly talk about your interests and hobbies outside of work, as well as any personal projects you may be working on.
• Ask questions. Asking questions shows you’re engaged in the conversation and gives you an opportunity to learn more about the company and the role.
• Don't be afraid to say you don't know. If you don't know something, explain how you would find out.

After the interview, send a thank-you note to the interviewer. Today, it can be as simple as shooting a message on Slack.

• How to Practice for Code Interviews

There are generally three types of questions in coding interviews: algorithm, data structure, and system design. Familiarize yourself with each type and practice solving them. 

Even experienced engineers struggle with coding interviews. You can practice for loops and sorting all you want, but when it comes down to it, you're being asked to solve a puzzle on command. All you can do is practice the fundamentals.

100 Front End Interview Questions Challenge

• Conclusion: Want to Become a Front-End Developer?

Congrats! You made it to the end of our giant list of front end developer interview questions. 

If you’re interested in becoming a front-end developer, there are a few things you should keep in mind. First, it’s important to have a strong understanding of HTML, CSS, and JavaScript. You should also be familiar with various front-end frameworks and libraries, as well as tools like Gulp and Grunt. And lastly, don’t forget the importance of soft skills like communication and problem-solving to be successful in this role.

Those are all the front end developer questions we have. What are your next steps? Consider expanding your knowledge with a course!

Take One of the Best Web Developer Courses!

• Frequently Asked Questions

1. What are Front-end Interviews Like?

Front-end interviews tend to focus on technical skills, such as your knowledge of HTML, CSS, and JavaScript. You may also be asked questions about various front-end frameworks and libraries, determined by the systems you are interviewing for. There may be a great chasm between a front-end developer for iOS and a front-end developer for web applications.

2. Is a Front-end Interview Hard?

If you know your stuff, it shouldn't be. While your average front end development interview questions will be straightforward, code questions can make people nervous. You will frequently undergo coding interviews in JavaScript, which might involve iterating through loops or other basic tasks that a front-end developer may not frequently be do otherwise.

3. What Skills Does a Front-end Developer Need?

You’ll need a solid understanding of HTML, JavaScript, and CSS. Additionally, basics of User Interface design User Experience design knowledge helps immensely. A front-end developer is frequently called upon for design mechanics as much as technical components.

Jenna Inouye currently works at Google and has been a full-stack developer for two decades, specializing in web application design and development. She is a tech expert with a B.S. in Information & Computer Science and MCITP certification. For the last eight years, she has worked as a news and feature writer focusing on technology and finance, with bylines in Udemy, SVG, The Gamer, Productivity Spot, and Spreadsheet Point.

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50 Common Front End Developer Interview Questions

Front-end development involves the building of webpages and user interfaces for web applications. Front-end developers implement the structure, design, behavior, and animation of everything you see on the screen when you open up websites, web applications, or mobile apps.

Q1 :   Explain meta tags in HTML

• Meta tags always go inside head tag of the HTML page
• Meta tags is always passed as name/value pairs
• Meta tags are not displayed on the page but intended for the browser
• Meta tags can contain information about character encoding , description , title of the document etc,

Q2 :   Name some basic design elements

The elements of design are:

• LINE – The linear marks made with a pen or brush or the edge created when two shapes meet.
• SHAPE – A shape is a self contained defined area of geometric (squares and circles), or organic (free formed shapes or natural shapes). A positive shape automatically creates a negative shape.
• DIRECTION – All lines have direction – Horizontal, Vertical or Oblique. Horizontal suggests calmness, stability and tranquillity. Vertical gives a feeling of balance, formality and alertness. Oblique suggests movement and action
• SIZE – Size is simply the relationship of the area occupied by one shape to that of another.
• TEXTURE – Texture is the surface quality of a shape – rough, smooth, soft hard glossy etc.
• COLOUR – Colour is light reflected off objects. Color has three main characteristics: hue or its name (red, green, blue, etc.), value (how light or dark it is), and intensity (how bright or dull it is).

Q3 :   What Is Load Balancing?

Load balancing is simple technique for distributing workloads across multiple machines or clusters. The most common and simple load balancing algorithm is Round Robin. In this type of load balancing the request is divided in circular order ensuring all machines get equal number of requests and no single machine is overloaded or underloaded.

The Purpose of load balancing is to

• Optimize resource usage (avoid overload and under-load of any machines)
• Achieve Maximum Throughput
• Minimize response time

Most common load balancing techniques in web based applications are

• Round robin
• Session affinity or sticky session
• IP Address affinity

Q4 :   What npm is used for?

npm stands for Node Package Manager. npm provides the following two main functionalities:

• Online repositories for Node.js packages/modules which are searchable on search.nodejs.org
• Command-line utility to install packages, do version management and dependency management of Node.js packages.
• Another important use for npm is dependency management . When you have a node project with a package.json file, you can run npm install from the project root and npm will install all the dependencies listed in the package.json.

Q5 :   What is SQL injection?

Injection attacks stem from a lack of strict separation between program instructions (i.e., code) and user-provided (or external) input. This allows an attacker to inject malicious code into a data snippet.

SQL injection is one of the most common types of injection attack. To carry it out, an attacker provides malicious SQL statements through the application.

How to prevent:

• Prepared statements with parameterized queries
• Stored procedures
• Input validation - blacklist validation and whitelist validation
• Principle of least privilege - Application accounts shouldn’t assign DBA or admin type access onto the database server. This ensures that if an application is compromised, an attacker won’t have the rights to the database through the compromised application.

Q6 :   What is Scope in JavaScript?

In JavaScript, each function gets its own scope . Scope is basically a collection of variables as well as the rules for how those variables are accessed by name. Only code inside that function can access that function's scoped variables.

A variable name has to be unique within the same scope. A scope can be nested inside another scope. If one scope is nested inside another, code inside the innermost scope can access variables from either scope.

Q7 :   What is webpack?

Webpack is a build tool that puts all of your assets, including Javascript, images, fonts, and CSS, in a dependency graph. Webpack lets you use require() in your source code to point to local files, like images, and decide how they're processed in your final Javascript bundle, like replacing the path with a URL pointing to a CDN.

Q8 :   Why and when should I Use Webpack?

If you're building a complex Front End application with many non-code static assets such as CSS, images, fonts, etc, then yes, Webpack will give you great benefits.

If your application is fairly small, and you don't have many static assets and you only need to build one Javascript file to serve to the client, then Webpack might be more overhead than you need.

Q9 :   Explain the CSS box model and the layout components that it consists of

The CSS box model is a rectangular layout paradigm for HTML elements that consists of the following:

• Content - The content of the box, where text and images appear
• Padding - A transparent area surrounding the content (i.e., the amount of space between the border and the content)
• Border - A border surrounding the padding (if any) and content
• Margin - A transparent area surrounding the border (i.e., the amount of space between the border and any neighboring elements)

Q10 :   How JavaScript and jQuery are different?

JavaScript is a language While jQuery is a library built in the JavaScript language that helps to use the JavaScript language.

Q11 :   What are advantages of REST web services?

Some of the advantages of REST web services are:

• Learning curve is easy since it works on HTTP protocol
• Supports multiple technologies for data transfer such as text, xml, json, image etc.
• No contract defined between server and client, so loosely coupled implementation.
• REST is a lightweight protocol
• REST methods can be tested easily over browser.

Q12 :   What is Content Security Policy?

Content Security Policy (CSP) is an HTTP header that allows site operators fine-grained control over where resources on their site can be loaded from. The use of this header is the best method to prevent cross-site scripting (XSS) vulnerabilities. Due to the difficulty in retrofitting CSP into existing websites, CSP is mandatory for all new websites and is strongly recommended for all existing high-risk sites.

The primary benefit of CSP comes from disabling the use of unsafe inline JavaScript. Inline JavaScript – either reflected or stored – means that improperly escaped user-inputs can generate code that is interpreted by the web browser as JavaScript. By using CSP to disable inline JavaScript, you can effectively eliminate almost all XSS attacks against your site.

Q13 :   What is Cross-Site Scripting (XSS)?

Cross-Site Scripting (XSS) is an attack that occurs when an attacker uses a web application to send malicious code, generally in the form of a browser side script, to a different end user.

The page provided by the server when someone requests it is unaltered. Instead, an XSS attack exploits a weakness in a page that include a variable submitted in a request to show up in raw form in the response. The page is only reflecting back what was submitted in that request.

Q14 :   What is User Centered Design?

User-centered design is an iterative design process in which designers focus on the users and their needs in each phase of the design process. UCD calls for involving users throughout the design process via a variety of research and design techniques so as to create highly usable and accessible products for them.

User-centered design demands that designers employ a mixture of investigative (e.g., surveys and interviews) and generative (e.g., brainstorming) methods and tools to develop an understanding of user needs.

Q15 :   What is Callback Hell and what is the main cause of it?

Asynchronous JavaScript, or JavaScript that uses callbacks, is hard to get right intuitively. A lot of code ends up looking like this:

See the pyramid shape and all the }) at the end? This is affectionately known as callback hell .

The cause of callback hell is when people try to write JavaScript in a way where execution happens visually from top to bottom. Lots of people make this mistake! In other languages like C, Ruby or Python there is the expectation that whatever happens on line 1 will finish before the code on line 2 starts running and so on down the file.

Q16 :   What is Encapsulation ?

Encapsulation is defined as the process of enclosing one or more items within a physical or logical package . Encapsulation, in object oriented programming methodology, prevents access to implementation details.

Q17 :   What is Polymorphism ?

The word polymorphism means having many forms. In object-oriented programming paradigm, polymorphism is often expressed as one interface, multiple functions .

Q18 :   What is Sass ?

Sass or Syntactically Awesome StyleSheets is a CSS preprocessor that adds power and elegance to the basic language. It allows you to use variables, nested rules, mixins, inline imports, and more, all with a fully CSS-compatible syntax. Sass helps keep large stylesheets well-organized, and get small stylesheets up and running quickly.

A CSS preprocessor is a scripting language that extends CSS by allowing developers to write code in one language and then compile it into CSS.

Q19 :   What is strict mode ?

Strict Mode is a new feature in ECMAScript 5 that allows you to place a program, or a function, in a "strict" operating context. This strict context prevents certain actions from being taken and throws more exceptions.

Q20 :   What is a CSS rule ?

Web browsers apply CSS rules to a document to affect how they are displayed. A CSS rule is formed from:

• A set of properties , which have values set to update how the HTML content is displayed,
• A selector , which selects the element(s) you want to apply the updated property values to.

A set of CSS rules contained within a stylesheet determines how a webpage should look.

Q21 :   What is meant by the KISS principle?

KISS , a backronym for "keep it simple, stupid", is a design principle noted by the U.S. Navy in 1960. The KISS principle states that most systems work best if they are kept simple rather than made complicated; therefore simplicity should be a key goal in design, and that unnecessary complexity should be avoided.

Q22 :   What is the difference between span and div?

• div is a block element
• span is inline element

For bonus points, you could point out that it’s illegal to place a block element inside an inline element, and that while div can have a p tag, and a p tag can have a span , it is not possible for span to have a div or p tag inside.

Q23 :   Why do we use jQuery?

Due to following advantages.

• Easy to use and learn.
• Easily expandable.
• Cross-browser support (IE 6.0+, FF 1.5+, Safari 2.0+, Opera 9.0+)
• Easy to use for DOM manipulation and traversal.
• Large pool of built in methods.
• AJAX Capabilities.
• Methods for changing or applying CSS, creating animations.
• Event detection and handling.
• Tons of plug-ins for all kind of needs.

Q24 :   How does concurrency work in Node.js?

The thing with node.js is that everything runs concurrently, except for your code .

So, what that means is that there are actually lots of threads running inside Node.js virtual machine (or a thread pool if you wish), and those threads are utilized whenever you call an async function like performing i/o operations on files, accessing databases, requesting urls, etc.

However, for your code, there is only a single thread, and it processes events from an event queue . So, when you register a callback its reference is actually passed to the background worker thread, and once the async operation is done, new event is added to the event-queue with that callback

When Node gets I/O request it creates or uses a thread to perform that I/O operation and once the operation is done, it pushes the result to the event queue . On each such event, event loop runs and checks the queue and if the execution stack of Node is empty then it adds the queue result to execution stack.

This is how Node manages concurrency.

Q25 :   Mention what is the difference between PUT and POST?

PUT puts a file or resource at a particular URI and exactly at that URI. If there is already a file or resource at that URI, PUT changes that file or resource. If there is no resource or file there, PUT makes one

POST sends data to a particular URI and expects the resource at that URI to deal with the request. The web server at this point can decide what to do with the data in the context of specified resource

PUT is idempotent meaning, invoking it any number of times will not have an impact on resources.

However, POST is not idempotent , meaning if you invoke POST multiple times it keeps creating more resources

Q26 :   Name fundamental principles of design

The fundamental principles of design are:

• BALANCE  — Balance in design is similar to balance in physics. A large shape close to the center can be balanced by a small shape close to the edge. Balance provides stability and structure to a design. It’s the weight distributed in the design by the placement of your elements.
• PROXIMITY  — Proximity creates a relationship between elements. It provides a focal point. Proximity doesn’t mean that elements have to be placed together, it means they should be visually connected in some way.
• ALIGNMENT  — Allows us to create order and organization. Aligning elements allows them to create a visual connection with each other.
• REPETITION  — Repetition strengthens a design by tying together individual elements. It helps to create association and consistency. Repetition can create rhythm (a feeling of organized movement).
• CONTRAST  — Contrast is the juxtaposition of opposing elements (opposite colors on the color wheel, or value light/dark, or direction — horizontal/vertical). Contrast allows us to emphasize or highlight key elements in your design.
• SPACE  — Space in art refers to the distance or area between, around, above, below, or within elements. Both positive and negative space are important factors to be considered in every design.

Q27 :   What are defer and async attributes on a <script> tag?

If neither attribute is present, the script is downloaded and executed synchronously, and will halt parsing of the document until it has finished executing (default behavior). Scripts are downloaded and executed in the order they are encountered.

The defer attribute downloads the script while the document is still parsing but waits until the document has finished parsing before executing it, equivalent to executing inside a DOMContentLoaded event listener. defer scripts will execute in order.

The async attribute downloads the script during parsing the document but will pause the parser to execute the script before it has fully finished parsing. async scripts will not necessarily execute in order.

Note: both attributes must only be used if the script has a src attribute (i.e. not an inline script).

100+ Front-end developer questions and answers for 2024

Are you a front-end developer looking to build your career? Or, are you a recruiter hunting for exceptionally talented front-end developers? If the answer to at least one of them is yes, you have come to the right place. This list of meticulously selected front-end developer interview questions can help you in acing your front-end developer interview, regardless of whether you are a front-end developer or a recruiter looking for one.

Last updated on May 15, 2024

As the digital world evolves with relentless speed, the demand for skilled front-end developers who can create interactive and user-friendly interfaces continues to grow. Whether you're a seasoned developer looking to stay sharp in the latest trends and techniques or a hiring manager aiming to sift through the best talent in the industry, this blog is your go-to guide.

In this blog, we have compiled the most relevant and insightful questions and answers that reflect the state of front-end development in 2024. Covering a broad spectrum of topics from fundamental concepts to cutting-edge technologies, this blog is designed to boost technical proficiency, enhance interview preparation, and ensure you're equipped with the knowledge to excel in the ever-changing landscape of front-end development.

Table of contents

Basic front-end interview questions and answers.

What is the purpose of the HTML 'doctype' declaration?

The 'doctype' declaration is an instruction to the web browser about what version of HTML the page is written in. It stands for "Document Type Declaration" and is actually a prerequisite for HTML documents that tells the browser how to interpret the content. While it doesn't specify a version per se (such as HTML 4.01 or XHTML), in modern HTML (HTML5), the declaration is simplified to just <!DOCTYPE html>, asserting that the document should be processed as HTML5, the current standard.

 How would you create a hyperlink in HTML?

To create a hyperlink in HTML, you indeed use the anchor (<a>) element, combined with an href (hypertext reference) attribute that specifies the destination URL. For example: <a href="https://www.example.com">Click here to visit Example.com</a>

This markup creates a clickable text that says "Click here to visit Example.com". When a user clicks on this link, they will be directed to the specified URL (https://www.example.com).

What is the purpose of using doctypes in HTML?

You've probably noticed a declaration before the tag in an HTML page. The element in HTML is used to tell the browser what version of HTML is being used in the page. This document type declaration is called (DTD).

The doctype declaration varies depending on the HTML version.

How will you navigate the DOM with JavaScript?

Either getElementById or querySelector may be used to obtain a DOM node. Then, by calling .childNodes you may receive all of its children (note: childNodes does not return an Array, but a NodeList). To traverse the DOM, you can iterate through the childNodes by calling childNodes on each one of them. You may retrace your steps by looking at the parentNode of any node.

What are the disadvantages of using CSS preprocessors?

Some significant disadvantages of using CSS preprocessors are:

• Compilation times may take longer than expected. This is because you must translate every SASS file to CSS before building it.
• Because it combines several CSS files, the primary file might get rather huge. This increases the time it takes to execute a request.
• There is a longer learning curve since the user must have a thorough grasp of the preprocessor before using it.

Differentiate between synchronous and asynchronous functions?

Synchronous methods: Synchronous functions prevent the application from running until the file operation is completed. Blocking functions is another name for these functions. The last argument in synchronous methods is File Descriptor. A file descriptor is a reference to files that have been opened. It's a number or a file reference id returned after using the fs module's fs.open() function to open the file. By putting "Sync" to the function name, all asynchronous methods may be made to run synchronously.

Asynchronous functions do not stall the program's execution, and each instruction is performed after the one before it, even if the prior command hasn't computed the result. The preceding command keeps running in the background until it is complete and then loads the result. As a result, these functions are referred to as non-blocking functions. The last parameter expected is a callback function. Asynchronous functions are often favored over synchronous functions because they do not prevent the program from running until it has completed processing, whereas synchronous functions do.

Talk about Load Balancing.

Load balancing is a way of allocating and processing requests across several devices rather than a single device. This guarantees that the load is distributed efficiently and does not rely on a single location.

Round Robin is the most often utilized load balancing technique. The requests are dispersed over a collection of servers in this approach. The algorithm distributes requests to the servers and then returns to the top to restart the process.

What do you understand by semantic HTML?

The right use of HTML to reinforce the meaning of material on a web page, rather than only specify its look, is known as semantic HTML.

Search engines, screen readers, and other user devices can employ semantically valid HTML to assess the importance and context of web content. Appropriate HTML components are chosen based on their intrinsic meaning rather than how they seem aesthetically on a produced web page in order to reflect the essence of information effectively.

Offer some suggestions regarding how to fix a browser-specific styling issue.

• Using server-side rendering, we can construct a unique stylesheet for each browser.
• Another option is to use a package such as Bootstrap, which already contains the code to deal with the browser-specific styling problem.
• Reset and Normalize CSS are also options.
• Many third-party plugins include libraries to help with browser style.

What do you know about reflow? Mention some ways to avoid it.

When one element's layout, window size, or other properties are altered, the position of all subsequent elements changes as well. This, in turn, impacts the page's flow, which is referred to as reflow.

You may avoid reflow by using the following methods:

• It's best to avoid using several inline styles.
• Avoid using tables in your design.
• Only use animations on fixed or absolute items.

What do you think, are window.onload and document.onload fired simultaneously?

No, window.onload and document.onload are not fired simultaneously. When the DOM is ready, Document.onload is called. This can happen before or after the pictures, scripts, and other information have been loaded.

Window.onload, on the other hand, is only invoked after the DOM is fully loaded and ready with all content, including images, scripts, and CSS.

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Explain the difference between 'id' and 'class' attributes in HTML.

In HTML, both the 'id' and 'class' attributes are used to identify HTML elements for styling with CSS, manipulation with JavaScript, or for general organization of the document structure. Here are the key differences:

The 'id' attribute is used to provide a unique identifier to an HTML element. It must be unique within the whole document, meaning that no two elements should have the same 'id' value. In contrast, the 'class' attribute can be shared across multiple elements. Multiple elements can have the same 'class' value, allowing for group styling and selection.

Because 'id' is unique, when it is used with JavaScript methods like getElementById(), it will only return one element. On the contrary, when 'class' names are used with methods like getElementsByClassName(), it returns a collection of elements and additional steps may be necessary to work with individual elements.

Moreover, the 'id' is also used as a fragment identifier in URLs. For instance, appending #uniqueElement to the URL would scroll the page to the element with that 'id'.

Describe the 'box model' in CSS.

The box model in CSS defines how elements are structured with content, padding, borders, and margins. It consists of four parts: content, padding, border, and margin. The total width or height of an element is calculated by adding these components together. The CSS box model is a fundamental concept in web design and layout that describes how every element on a web page is modeled as a rectangular box. 

How can you center an element horizontally using CSS?

Horizontal centering of an element in CSS can be achieved in several ways, depending on the layout and structure of the HTML elements. One of the most classic techniques, as mentioned, is to use auto margins with a defined width for block-level elements.

Here is an example:

.center-element {

  margin-left: auto;

  margin-right: auto;

  width: 50%; /* or any fixed width */

This technique works well with block-level elements that have a width less than their container's width.

What's the difference between 'let', 'const', and 'var' when declaring variables? 

let, const, and var are all used to declare variables in JavaScript, but they have different scopes and behaviors:

var : It is the oldest keyword for declaring variables, introduced in ES5 (older JavaScript standard). It can be either function-scoped or globally scoped if declared outside of a function. Variables declared with var are hoisted to the top of their scope, meaning the variable can be used before its declaration. This behavior can lead to unexpected outcomes, which is why var is often avoided in modern JavaScript.

function example() {

  if (true) {

    var x = 5;

  console.log(x); // Output: 5, x is accessible here due to function scoping

let : Introduced in ES6 (ECMAScript 2015), it provides block-level scoping, which means a variable declared with let can only be accessed within the block it was defined in. let also allows the variable to be reassigned.

const : Also introduced in ES6, const is similar to let in terms of block scoping, but it is used to create constants — values that cannot be reassigned once set. It's important to note that objects and arrays declared with const can still have their properties or items modified; it's only the reassignment of the variable itself that's disallowed.

  const pi = 3.14;

  pi = 1; // Uncaught TypeError: Assignment to constant variable.

How do you write a comment in JavaScript?

In JavaScript, comments are used to annotate the code, adding descriptions or explanations that are not executed by the browser. There are two types of comments in JavaScript:

Single-Line Comments: You can create a single-line comment by using two forward slash characters (//). Everything following // on the same line will be treated as a comment and ignored during execution.

// This is a single-line comment.

let x = 5; // This is another single-line comment.

Multi-Line Comments: For longer comments that span multiple lines, you use the /* to begin the comment and / to end it. Everything between / and */ will be treated as a comment.

/* This is a 

   multi-line comment.

It's important to note that single-line comments can't be nested, and multi-line comments should be used carefully to avoid accidentally commenting out essential parts of the code or unbalancing comment delimiters.

Explain the concept of data types in JavaScript.

In JavaScript, data types broadly categorize the kind of data values that can be stored and manipulated within the language. They are classified into two main categories: primitive types and reference (or complex) types.

• Primitive Types: These are the basic data types that represent single values and cannot be broken down into smaller elements. They are immutable, which means that their values cannot be altered once created. 
• Reference Types (Complex Types): These types represent objects and functions that may be made up of multiple values and can be altered.

How can you check if a variable is an array in JavaScript?

In JavaScript, the Array.isArray() method is the most reliable way to determine whether a variable is an array. This is because arrays in JavaScript are a specialized kind of object, and using other methods, such as checking the variable's type with typeof, will simply return 'object' rather than 'array'. Here's an example of using Array.isArray():

let myVariable = [1, 2, 3];

if (Array.isArray(myVariable)) {

  console.log('myVariable is an Array!');

  console.log('myVariable is not an Array.');

What's the purpose of the 'NaN' value in JavaScript?

'NaN', standing for "Not-a-Number", is a special value in JavaScript that is part of the Number data type. It arises as a result of an operation that doesn't result in a well-defined numerical outcome. This could be because of an invalid mathematical operation or a failed attempt to convert a non-numeric value to a number.

Define the difference between HTTP and HTTPS.

HTTP (Hypertext Transfer Protocol) is the foundational protocol used for transmitting data on the web—specifically, it governs the communication between web browsers and servers. It is a stateless protocol, meaning it doesn't retain any information about previous web sessions. HTTP's major drawback is that the data is not encrypted, making it vulnerable to eavesdropping, interception, and man-in-the-middle attacks. When data is sent or received via HTTP, it's in plaintext, which could potentially expose sensitive information to unauthorized parties.

HTTPS (Hypertext Transfer Protocol Secure), on the other hand, includes a layer of security through the use of SSL/TLS (Secure Socket Layer/Transport Layer Security) encryption. This cryptographic protocol creates an encrypted link between the user's browser and the server, ensuring that all data transmitted is unreadable to anyone except for the recipient. HTTPS is critical for maintaining data integrity and protecting the privacy and security of user information—especially in transactions involving sensitive data such as login credentials, payment information, and personal data.

While HTTP and HTTPS perform the same basic function—transmitting data over the web—HTTPS provides a secure transport layer through encryption that protects the data from eavesdroppers, making it the preferred choice for nearly all web communication today.

Explain the purpose of the 'meta' tag in HTML.

The 'meta' tag in HTML is used to provide metadata about the document such as character encoding ('charset'), viewport settings for responsive design, authorship information, and more. It's not displayed on the web page but provides important information to browsers and search engines.

What does the term 'responsive design' mean? 

Responsive design is an approach to web design aimed at creating web pages that provide an optimal viewing and interaction experience across a wide range of devices. It involves ensuring that a website is easily navigable and readable on different screen sizes, from large desktop monitors to the smallest mobile phones.

How would you clear the cache of a web browser?

Users can clear their browser cache through the browser's settings or preferences. As a developer, you can't directly clear a user's cache, but you can use techniques like cache busting to ensure users receive updated assets.

Describe the role of DNS in web development.

DNS, or Domain Name System, is often referred to as the "phone book of the internet." It plays a pivotal role in web development by translating human-readable domain names (such as www.example.com) into machine-readable IP addresses (like 192.0.2.1). This process, known as DNS resolution, allows users to access websites using easy-to-remember names rather than numeric IP addresses. When a user enters a web address in their browser, the DNS system is queried to find the corresponding IP address for that domain name. 

How do media queries work in responsive design?

Media queries are a feature of CSS that became a cornerstone of responsive design with the introduction of CSS3. They allow developers to conditionally apply CSS styles based on the media type (such as screen or print) and specific characteristics of the user's device, primarily the viewport size.

Media queries consist of a media type and can include one or more expressions, which can evaluate to either true or false. When the expressions evaluate as true, the corresponding block of CSS rules are applied to the document. Commonly used expressions are related to viewport dimensions (width, height), device orientation (orientation), and resolution (resolution).

Explain the 'float' property in CSS. Is it still relevant today?

The float property in CSS originates from the intent to allow elements to behave like inline blocks around which text could wrap, similar to images in a magazine layout. For example, float: left; would cause an element to shift to the left side of its containing element, allowing text and inline elements to flow around its right side.

While the primary use of float was to wrap text around images, it was also widely repurposed by web developers to create entire web layouts. However, this sometimes led to complex and fragile CSS code, as floats weren't initially meant for structured layout purposes.

What's the difference between 'inline' and 'inline-block' display properties?

The inline and inline-block display properties in CSS dictate how elements are formatted within a document.

• An element with display: inline; will not start on a new line and will only occupy just enough width it requires. Height and width properties do not affect inline elements.
• Inline elements do not respect the top and bottom margins or paddings set on them. They do, however, respect left and right margins and horizontal padding.
• They are typically used for content that is part of a flow of text, such as <a>, <span>, or <strong> tags.

inline-block:

• An element with display: inline-block; allows you to set a width and height on the element, which is not possible with inline elements.
• Unlike block elements that take up the full width available and respect all margins and padding, inline-block elements allow other elements to sit to their left and right. They respect all padding and margins on all sides.
• inline-block is useful for creating a layout of horizontally aligned elements that also require height and width, such as a horizontal menu.

In practice, inline-block elements are block-level elements that flow just like inline elements, which gives them the utility of both layout forms. Before flexbox and grid became widely used, inline-block was a popular choice for creating complex, horizontally-aligned layouts that required fine-grained control over the size and spacing of individual elements.

How can you vertically align an element using CSS?

You can vertically align an element by using the 'display: flex;' property on its parent and setting 'align-items: center;' to vertically center the child elements. Alternatively, you can use the 'vertical-align' property for inline or inline-block elements within their container.

Flexbox makes vertical centering straightforward. To vertically align an element within a flex container, you would indeed set display: flex; on the parent and use align-items: center; for the children elements.

While the vertical-align property is specifically used for inline or inline-block elements, and it aligns the content inside a line box or a cell in a table. Note that vertical-align does not apply to block-level elements and shouldn't be used to vertically center block-level elements in a container.

What's the purpose of CSS preprocessors like SASS and LESS?

CSS preprocessors like SASS and LESS are powerful tools that introduce programming constructs into CSS, which is a stylesheet language that was originally designed to be simple and straightforward but lacks some of the nuanced capabilities found in programming languages. Preprocessors process code written in the preprocessor's language and compile it into standard CSS code so that browsers can render it.

Intermediate front-end interview questions and answers

What is a closure in JavaScript? Provide an example.

In JavaScript, a closure is a function that remembers the variables from the scope in which it was created, even after that scope has finished executing. It essentially "closes over" the variables it needs. This allows for data encapsulation and the creation of private variables in JavaScript.

function createCounter() { let count = 0; return function() { count++; return count; }; } const counter = createCounter(); console.log(counter()); // Output: 1 console.log(counter()); // Output: 2 

Explain the concept of hoisting in JavaScript.

Hoisting is a JavaScript behavior where variable and function declarations are moved to the top of their containing scope during compilation, regardless of where they are declared. However, only the declarations are hoisted, not the initializations. This means that you can use a variable or a function before it's declared in the code.

How do you handle errors in asynchronous JavaScript code?

In asynchronous JavaScript , errors can be handled using try-catch blocks or using the .catch() method on promises. When using async/await, you can wrap the awaited code within a try-catch block to catch any errors that might occur during execution.

Example with Promises:

fetch('https://api.example.com/data') .then(response => response.json()) .catch(error => console.error('Error fetching data:', error)); 

 What's the difference between 'null' and 'undefined'?

In JavaScript, both null and undefined signify an absence of value, but they represent different concepts:

undefined is the default value of a variable that has been declared but not yet assigned a value. It is also the value returned by a function that does not explicitly return any value, or the value of an object property or array element that does not exist.

Example of undefined:

let variable; // Declared but not assigned

console.log(variable); // Logs: undefined

null is an assignment value that can be assigned to a variable as a representation of no value. It is an intentional absence of any object value. In contrast to undefined, null is something that must be assigned by the code's author to explicitly indicate that "this variable should have no value".

Example of null:

let variable = null; // Assigned the value null

console.log(variable); // Logs: null

How would you iterate over the properties of an object in JavaScript?

You can iterate over the properties of an object using a for...in a loop or the Object.keys() , 

Object.values() , or Object.entries() methods introduced in ES6.

Example of using for...in loop:

const obj = { a: 1, b: 2, c: 3 }; for (const key in obj) { console.log(`${key}: ${obj[key]}`); } 

Describe the basic workflow when using Git for version control.

The basic Git workflow involves creating a repository, making changes to code, staging those changes, committing them, and then pushing them to a remote repository.

• Create or clone a repository.
• Make changes to your files.
• Stage the changes using git add command.
• Commit the staged changes with a message using git commit .
• Push the committed changes to a remote repository using git push .

Explain the difference between Git's 'rebase' and 'merge' commands.

The git merge command is used to integrate changes from one branch into another. A merge takes the contents of a source branch and integrates them with a target branch. In the case there are divergent commits on both branches, Git will create a "merge commit," a new commit that ties together the histories of both branches, resulting in a bifurcating commit history.

This merged history shows all of the commits from both branches, preserving the context of parallel or collaborative development workflows. It is the safest operation for combining branches and is the most commonly used in collaborative environments because it doesn't rewrite history, which can be disruptive to other team members.

On the other hand, the git rebase command rewrites the commit history by moving the entire feature branch to start from the tip of the target branch. Effectively, it takes all the changes that were committed on one branch and reapplies them on the base of another branch.

This results in a linear commit history, as it looks like all changes were made in a sequence, even if they originally happened in parallel. Rebasing can simplify commit history and remove unnecessary merge commits. However, because rebase alters commit history, it can be dangerous to use on shared branches where others may have based work on the existing commits. Rebasing can lead to significant confusion and requires a force push (git push -f) to update the history on remote repositories.

What are continuous integration (CI) and continuous deployment (CD)?

Continuous integration (CI) is a development practice where code changes are automatically 

built, tested, and integrated into a shared repository multiple times a day. It helps identify and fix integration issues early.

Continuous deployment (CD) takes CI a step further by automatically deploying code changes 

to production or staging environments after passing CI tests. This allows for rapid and frequent releases.

How can you optimize website loading speed?

• Minimize and compress assets like JavaScript, CSS, and images.
• Use browser caching to store frequently used assets locally.
• Reduce HTTP requests by combining and minifying files.
• Use a content delivery network (CDN) to distribute assets.
• Prioritize visible content and lazy-load non-critical resources.
• Optimize images for the web using appropriate formats and sizes.

What's the purpose of a content delivery network (CDN)?

A content delivery network (CDN) is a network of distributed servers that work together to deliver web content, such as images, stylesheets, scripts, and videos, to users based on their geographic locations. The purpose of a CDN is to improve the performance and loading speed of websites by reducing the distance between the user and the server, thus minimizing latency and distributing server load.

Explain the key differences between CSS grid and flexbox layout systems.

CSS grid is a 2-dimensional layout system that is ideal for creating complex grid-based layouts. It works horizontally and vertically, allowing you to control rows and columns with precision.

Flexbox , on the other hand, is a 1-dimensional layout system designed for simpler layouts where elements need to be aligned in a row or column. It's great for handling the alignment, distribution, and reordering of elements within a single axis.

What is CSS-in-JS? List its advantages and disadvantages.

CSS-in-JS is an approach where you write CSS code as JavaScript objects in your JavaScript files. This allows for dynamic styling based on component props or states.

Advantages:

• Scoped styles to global conflicts.
• Dynamic styles based on component logic.
• No need for external CSS files.
• Better optimization and elimination of unused styles.

Disadvantages:

• Learning curve for developers new to the approach.
• Potential impact on browser caching.
• Complex tooling and building configuration.

How can you create a smooth CSS animation? Provide an example.

To create a smooth CSS animation, use the transition property or the @keyframes rule. Be sure to use easing functions and optimize properties for hardware acceleration.

Example using the transition property:

.element { transition: transform 0.3s ease-in-out; } .element:hover { transform: scale(1.2); }

Describe the 'position' property in CSS along with its possible values.

The position property in CSS is a fundamental concept used to control the layout of elements on a web page. It specifies how an element should be positioned within its parent context. There are five key values that the position property can take:

• static: Default value. Element follows the normal document flow.
• relative: Positioned relative to its normal position. Other elements are not affected.
• absolute: Positioned relative to its closest positioned ancestor or the containing block.
• fixed: Positioned relative to the viewport. Remains in the same position even when scrolled.
• sticky: Acts like a relative within its container until it crosses a threshold and then becomes fixed .

How would you implement a custom font on a website?

To implement a custom font on a website, use the @font-face rule in your CSS to specify the font's source and format. Then, apply the font to the desired elements using the font-family property.

@font-face { font-family: 'CustomFont'; src: url('path-to-font.woff2') format('woff2'), url('path-to-font.woff') format('woff'); } body { font-family: 'CustomFont', sans-serif; }

What is the 'this' keyword in JavaScript and how does it work?

The "this" keyword in JavaScript refers to the current execution context or the object that the function is a method of. Its value depends on how the function is called:

• In a regular function, this refers to the global object (in non-strict mode) or undefined (in strict mode).
• In a method, this refers to the object that the method is called on.
• With call() , apply() , or bind() , you can explicitly set the value of this .

Explain the differences between ES6 classes and constructor functions.

ES6 classes and constructor functions are used to create objects, but classes provide a more organized and syntactically cleaner way of defining object blueprints.

Differences:

• Classes support inheritance using the extends keyword.
• Constructor functions can be more error-prone due to forgetting to use new ones.
• Classes can define getter and setter methods using get and set .
• Classes are more readable and have a clearer syntax for creating objects.

How does prototypal inheritance work in JavaScript?

In JavaScript, objects can inherit properties and methods from other objects through their prototype chain. When you access a property or method on an object, if the object doesn't have it, JavaScript looks up the prototype chain until it finds the property or reaches the end.

This is achieved by setting the prototype of one object to be another object. When a property or method is not found on the current object, JavaScript checks the prototype object and continues up the chain until it finds the desired property or reaches the top, usually Object.prototype .

What are web workers and how can they improve performance?

Web workers are a feature in HTML5 that allow you to run JavaScript code in the background without blocking the main thread. They enable multitasking by running scripts in separate threads, which can significantly improve performance and responsiveness especially for computationally intensive tasks.

By offloading tasks to Web Workers, the main thread remains available for user interactions. This prevents UI freezes and slowdowns.

How do you optimize JavaScript code for better performance?

• Minimize and compress code using tools like UglifyJS.
• Use efficient algorithms and data structures.
• Limit DOM manipulation and use techniques like object pooling.
• Optimize loops by reducing unnecessary iterations.
• Use event delegation to minimize event listeners.
• Implement lazy loading for resources.
• Avoid unnecessary function calls and variable reassignments.

  Describe the concept of single-page applications (SPAs) and their advantages.

Single-page applications (SPAs) are web applications that load a single HTML page and dynamically update content as the user interacts with the app. The page doesn't reload during navigation, and data is often fetched asynchronously.

• Faster user experience as only content changes are loaded.
• Reduced server load and bandwidth usage.
• Seamless and smooth transitions between sections.
• Improved user engagement due to a native app-like feel.

What's the significance of the 'same-origin policy' in web security?

The same-origin policy is a security feature in web browsers that restricts web pages from making requests to a different domain than the one that served the web page. This prevents malicious websites from making unauthorized requests to other websites on behalf of the user.

This policy helps protect user data and sensitive operations, as it prevents cross-site request forgery (CSRF) and other types of attacks.

Explain the differences between cookies, local storage, and session storage.

• Cookies: Cookies are data stored on the client's browser meant to persist stateful information (such as identification data) between page requests. They are automatically sent by the browser to the server with each HTTP request, which can be less efficient as it adds to the HTTP request size. Cookies are limited in size (approximately 4KB) and can be configured with expiry dates and scope (domain and path). They also have attributes to enhance security, such as HttpOnly and Secure, which can mitigate the risk of client-side script access and ensure transmission over secure protocols respectively.
• Local storage: Local Storage is part of the Web Storage API and provides a way to store larger amounts of data (typically up to 5-10MB) locally within the user's browser that persists even after the browser is closed and reopened. Unlike cookies, local storage is not sent to the server with every HTTP request, which can improve performance for applications that do not need to send this data to the server with each request. Data stored in local storage is accessible across browser sessions and tabs, provided they are from the same origin.
• Session storage: Session Storage is also part of the Web Storage API and is very similar to local storage in terms of API and capacity. However, data stored in session storage is bound to the session and is cleared when the page session ends — that is, when the page is closed or the browser is exit. This makes session storage a good option for data that should not persist permanently and is only relevant for the duration of an active page session, such as the state of the user interface or temporary application states.

 How would you ensure your website is accessible to all users?

• Use semantic HTML for proper screen reader interpretation.
• Provide alternative text for images using the alt attribute.
• Ensure proper color contrast for readability.
• Implement keyboard navigation and focus indicators.
• Test with screen readers and other assistive technologies.
• Follow the Web Content Accessibility Guidelines (WCAG) for compliance.

What is a progressive web app (PWA) and why would you develop one?

A Progressive Web App (PWA) is a type of web application designed to deliver a high-quality user experience irrespective of the network state or device capabilities. It takes advantage of the latest web technologies to bring native app-like features and performance to web applications.

Developing a PWA provides benefits like:

• Improved user experience with fast loading and offline capabilities.
• Increased engagement through push notifications.
• Wider reach as PWAs work on various devices and platforms.
• Lower development and maintenance costs compared to native apps.

 Explain the virtual DOM and its role in React.js.

The virtual DOM is a programming concept used by libraries like React to improve rendering performance. It's an abstraction of the real DOM that represents the UI elements as a lightweight, in-memory data structure.

When changes are made to a React component's state, a virtual representation of the updated UI is created. React then efficiently calculates the difference (diff) between the old and new virtual representations and applies only those changes to the real DOM. This minimizes expensive direct manipulation of the DOM.

Compare React.js and Vue.js in terms of their features and performance.

React.js and Vue.js are popular front-end JavaScript frameworks. React is known for its extensive ecosystem, community, and large-scale applications. Vue is praised for its simplicity, ease of integration, and relatively smaller learning curve.

In terms of performance, both frameworks use a virtual DOM approach that offers similar benefits. However, React's ecosystem is more mature and offers more advanced optimization tools for larger applications.

What's the purpose of a state management library like Redux in React?

State management libraries like Redux help manage the global state of a React application. They provide a centralized store where data is stored and components can access and update that data without complex prop passing.

Redux enforces a unidirectional data flow and makes it easier to manage complex interactions, data sharing, and synchronization across components, especially in larger applications.

How does two-way data binding differ in Angular and Vue.js?

Angular's two-way data binding is implemented through the [(ngModel)] directive, also often referred to as "banana in a box" syntax due to its visual structure. This directive creates a binding on a form element that allows for the bidirectional flow of data between the model (typically the component's class instance) and the view (the template or HTML file):

<!-- In Angular template -->

<input [(ngModel)]="username">

In this example, username is a property defined in the Angular component. Any changes to the input field by the user will instantly update the username property, and any changes to the username property from within the code will immediately update the input field's value.

Vue.js utilizes the v-model directive for its two-way data binding on form elements. When you use v-model, Vue.js creates a linkage between the input element and the application's state (the Vue instance's data). This linkage is automatically maintained, and changes made to one will reflect in the other:

<!-- In Vue.js template -->

<input v-model="username">

Here, username is part of Vue's reactive data object. Typing into the field updates username, and changing username programmatically will update the field's displayed value.

Differences in Binding Mechanism:

Angular's two-way data binding is part of its larger framework ethos and is tightly integrated with Angular's form handling. On the other hand, Vue's v-model is syntactic sugar built on top of Vue's reactive system and event handling; it abstracts the need to manually listen to input events and update data.

Additionally, in Angular, you sometimes need to import FormsModule or ReactiveFormsModule to leverage ngModel, particularly for form handling. Vue's v-model can be used without importing any additional libraries as it's a built-in directive provided by Vue.

Describe the concept of 'props' and 'state' in React.

• Props: Short for properties, props are inputs to a React component. They are data passed from a parent component to a child component and are read-only. Props allow components to communicate and share information.
• State: The state is a data structure that holds the component's dynamic data, which can change over time. Unlike props, which are external and immutable, the state is internal to the component and can be updated using the setState() method. When the state changes, the component re-renders.

How would you create a responsive image in HTML and CSS?

To create a responsive image, set its max-width property to 100% in CSS. This ensures that the image scales down proportionally to fit its container while maintaining its aspect ratio.

<img src="image.jpg" alt="Responsive Image" class="responsive-image"> 

.responsive-image { max-width: 100%; height: auto; } 

Explain the concept of CSS specificity and how it affects styling.

CSS specificity determines which CSS rules are applied when conflicting styles are targeting the same element. It's calculated based on the number of selectors, IDs, classes, and inline styles.

Higher specificity values win over lower ones. Inline styles have the highest specificity, followed by IDs, classes, and elements. Specificity is important to understand when troubleshooting styling conflicts and ensuring intended styles are applied.

What's the purpose of the 'localStorage' object in web browsers?

The localStorage object in web browsers provides a way to store key-value pairs locally in the user's browser. Unlike cookies, data stored in localStorage is not sent to the server with every HTTP request. It's often used for caching user preferences, session data, and other non-sensitive information.

 How do you prevent CSS styles from affecting a specific element?

You can prevent CSS styles from affecting a specific element by using more specific selectors for the desired styles. Alternatively, you can use the :not() pseudo-class or inline styles to override unwanted styles.

Example using :not() pseudo-class:

/* This style won't apply to elements with class 'special' */ :not(.special) { color: blue; } 

Describe the 'addEventListener' method in JavaScript.

The addEventListener method is used in JavaScript to attach an event handler to an HTML 

element. It allows you to listen for specific events on the element, such as clicks, keypresses, and mouse movements, and execute a function when the event occurs.

const button = document.getElementById('myButton'); button.addEventListener('click', function() { console.log('Button clicked'); }); 

Explain the purpose of the 'alt' attribute in HTML image tags.

The 'alt' attribute in HTML image tags ( <img> ) provides alternative text that's displayed if the image cannot be loaded or if the user is using a screen reader. It's important for accessibility and SEO as it describes the image's content to those who can't see it.

How can you make a div element a clickable link using HTML and CSS?

To make a div element clickable as a link, you can wrap it in an <a> (anchor) element and apply CSS styles to customize the appearance.

<a href="https://example.com" class="link-wrapper"> <div class="clickable-div">Click me</div> </a> 

.link-wrapper { display: inline-block; text-decoration: none; /* Remove underline from the link / } .clickable-div { / Your styling for the div */ } 

What's the difference between 'margin' and 'padding' in CSS?

In CSS, both margin and padding are properties that control the space around and inside elements, but they serve different purposes in the box model, which is the foundation of layout on the web.

The margin property defines the space around an element, outside of any defined borders. Margin does not have a background color, and it is completely transparent. The margin creates separation between the element and other elements in the document. Margins collapse vertically, which means that if two vertical margins meet, the larger one prevails, and no space is added.

Padding is the space between the content of the element and its border. Unlike margin, padding is inside the border, so it does have a background color when one is defined for the element. Padding increases the inner space of an element, effectively increasing the size of the box if a width and height are set.

How would you select all elements with a specific class using CSS selectors?

You can select all elements with a specific class using the class selector ( .classname ).

.my-class { /* Styles for elements with class 'my-class' */ }

Explain the difference between synchronous and asynchronous JavaScript.

• Synchronous JavaScript: Code execution occurs sequentially. Each task is completed before moving to the next. It can block the browser's main thread, potentially leading to a slower user experience.
• Asynchronous JavaScript: Code execution doesn't block the main thread. Asynchronous tasks, such as AJAX requests and timers, are executed independently and their results are handled when they are ready. This allows the browser to remain responsive during long-running operations. Promises, async/await, and callbacks are common tools for managing asynchronous operations.

Advanced front-end interview questions and answers

How can you change the text content of an HTML element using JavaScript?

To change the text content of an HTML element using JavaScript, select the element using methods like document.getElementById() , document.querySelector() , or others. Then, modify its textContent property to the desired new text. For example:

const element = document.getElementById('myElement'); element.textContent = 'New Text Content'; 

Describe the importance of the 'viewport' meta tag in web development.

The 'viewport' meta tag is crucial in responsive web development as it controls how a web page is displayed on various devices with different screen sizes. Without this tag, the browser might render the page as if it were on a desktop screen, leading to poor user experience on smaller devices. The tag's attributes like 'width=device-width' help adapt the content to the screen width, ensuring proper layout and readability.

What's the purpose of the 'data-*' attribute in HTML5?

The data-* attribute in HTML5 allows developers to store extra information on standard, semantic HTML elements without any other hacks such as non-standard attributes, extra properties on DOM, or Node misuse of existing attributes. This means developers can keep the structured data separate from the presentation layer, ensuring clean, maintainable HTML.

The name of a data-* attribute must begin with 'data-', followed by any lowercase name appropriate to the specific context. The stored data can then be accessed via JavaScript using the dataset property on the DOM elements.

How do you target the last child element of a parent using CSS?

To target the last child element within a parent container using CSS, you can use the :last-child pseudo-class. This selector matches every element that is the last child of its parent.

.parent-element > :last-child {

  /* Styles for the last child element */

In this example, any last child element inside .parent-element will be selected and styled according to the specified rules.

Explain the use of the 'transition' property in CSS for animations.

The 'transition' property in CSS enables smooth animations between different property states. It defines how a property change should be animated over a specified duration. For example, adding transition: width 0.3s ease-in-out; to an element's style would smoothly animate changes in its width with a 0.3-second duration using an ease-in-out timing function.

What's the role of the 'role' attribute in HTML accessibility?

The 'role' attribute is essential for enhancing the accessibility of web content. It specifies the semantic role of an element for assistive technologies like screen readers. By assigning appropriate roles like 'button', 'link', or 'heading', developers ensure that users with disabilities can understand and interact with the content effectively.

How can you handle cross-browser compatibility issues in CSS?

Cross-browser compatibility can be managed by following best practices such as:

• Use modern CSS features and properties supported by major browsers.
• Test on different browsers and devices during development.
• Utilize CSS vendor prefixes for experimental features.
• Consider using CSS reset or normalize to standardize styling across browsers.
• Leverage feature detection libraries like Modernizr to adapt to varying browser capabilities.

Describe the 'fetch' API in JavaScript and how it's used. 

The fetch API in JavaScript is a more powerful and flexible way to make asynchronous requests to servers, enabling developers to easily implement network requests for resources. It's part of the modern browser's Window and Worker GlobalScope, meaning it can be used both in the main JavaScript thread as well as web workers.

Unlike the older XMLHttpRequest, fetch provides a cleaner and more convenient API that uses Promises to handle results and errors, eliminating the need for callback functions, which can lead to more complex and nested code (often referred to as "callback hell"). It’s used like this:

fetch(url) .then(response => response.json()) .then(data => { // Process data }) .catch(error => { // Handle errors }); 

What is the 'async' attribute in script tags and why is it used?

The 'async' attribute in script tags specifies that the script should be executed asynchronously while not blocking the rendering of the page. This is useful for improving page load performance, especially for non-essential scripts. It allows the browser to continue rendering the page while fetching and executing the script in the background.

How would you horizontally center an element within another element using CSS?

Flexbox provides a powerful and flexible way to align content. When you want to horizontally center a single element or multiple elements within a parent element, setting display: flex and justify-content: center on the parent element is a clean and responsive-friendly method.

For example:

  display: flex;

  justify-content: center;

Here's the HTML structure this would apply to:

<div class="parent">

  <div class="child">Centered content</div>

</div>

In the example above, the .child element will be horizontally centered within .parent.

Explain the concept of event delegation in JavaScript.

Event delegation in JavaScript is a technique based on the fact that most events bubble from the target element up through the DOM tree until they reach the document object, unless the propagation is explicitly stopped. By leveraging event bubbling, we can create a single event listener on a parent element that can listen for and handle events that occur on its child elements.

Here's how event delegation works:

• An event happens on an element, and if it's the type of event that bubbles (like a 'click' or 'keypress' event), it starts traveling up the DOM tree.
• If a parent element has an event listener attached to it for that event type, the event triggers the listener's callback function, even though the event didn't directly happen on the parent.
• Inside the callback function, event.target can be used to access the actual element that was the original target of the event, and you can choose to run code conditionally based on that target.

What's the purpose of the 'target' attribute in HTML anchor tags?

The 'target' attribute specifies how the linked resource should be displayed when the user clicks the anchor link. Common values are '_blank' to open in a new tab/window and '_self' to open in the same tab/window. This attribute provides control over the navigation experience for users.

How do you create a fixed header that remains at the top of the page while scrolling?

To create a fixed header, use CSS with position: fixed on the header element. For instance:

.header { position: fixed; top: 0; left: 0; width: 100%; z-index: 1000; /* ensures it's above other content */ } 

Describe the 'rem' and 'em' units in CSS and their differences.

Both 'rem' (root em) and 'em' units are relative units in CSS. 'Em' is relative to the font size of the element itself while 'rem' is relative to the font size of the root (usually the 'html' element). 'Rem' units are often preferred for consistent scaling across the entire page, especially in responsive design.

What is a JavaScript callback? Provide an example scenario.

A JavaScript callback is a function that's passed as an argument to another function and is executed at a later time, often after an asynchronous operation completes. For example, in the 'addEventListener' method, the second argument is a callback function that is executed when the specified event occurs:

button.addEventListener('click', function() { console.log('Button clicked'); }); 

How would you create a gradient background in CSS?

To create a gradient background in CSS, use the 'linear-gradient' or 'radial-gradient' function within the 'background' property. For a linear gradient:

.element { background: linear-gradient(to bottom, #ff9900, #ff5500); } 

 Explain the role of the 'z-index' property in CSS.

The z-index property in CSS is used to control the stacking order of elements that have been explicitly positioned (meaning their position property is set to relative, absolute, fixed, or sticky). It allows you to specify which elements appear above or below others along the z-axis, which is analogous to bringing elements closer or pushing them farther away from the viewer's eye on the screen.

An element with a higher z-index value will appear on top of an element with a lower z-index if they overlap. The default z-index for elements is auto, which corresponds to a stacking order defined by the element's position in the HTML document (earlier elements in the markup below later ones). It's important to note that z-index only works on positioned elements and will have no effect on those with a position of static (the default).

How can you prevent form submission using JavaScript?

To prevent form submission, use the 'preventDefault()' method within a form's 'submit' event listener. This prevents the default behavior of the form, which is to submit to a server:

form.addEventListener('submit', function(event) { event.preventDefault(); // Perform custom actions }); 

Describe the difference between 'GET' and 'POST' HTTP methods.

'GET' and 'POST' are two widely used HTTP methods that facilitate the exchange of data between a client and a server.

The GET method is typically used for requesting data from a server. It appends the data to be sent as a series of name-value pairs at the end of the URL in a query string. Because this information is visible in the URL, it is suitable for non-sensitive data retrieval such as search queries or page navigation requests.

Example of a GET request in the URL: http://example.com/page?parameter=value&also=anotherValue

Conversely, the POST method is commonly used to send data to a server for updates or processing, and the data is included in the body of the HTTP request, not in the URL. This means that POST can handle larger data quantities and keep the data hidden from the URL, making it more suitable for transferring sensitive or private information, like form submissions with personal details. POST requests also are not limited to ASCII formats; they can send binary data as well.

What's the role of the 'defer' attribute in script tags?

The defer attribute is a boolean attribute that can be included in <script> tags to control when the associated script is executed. When a script tag has the defer attribute, it indicates to the browser that the script should be downloaded asynchronously while the HTML document is being parsed. However, the script's execution is deferred until the document parsing is fully completed, just before the DOMContentLoaded event is triggered.

How would you create a sliding menu that appears from the side of the page using CSS animations ?

You can create a sliding menu using CSS animations by applying a transition to the menu's position or width and toggling a class on the menu to trigger the animation. For instance: .menu { position: fixed; top: 0; left: -300px; /* initial position / width: 300px; transition: left 0.3s ease; } .menu.active { left: 0; / slide in when active class is added */ }

Explain the 'flexbox' layout system in CSS.

Flexbox, officially known as the Flexible Box Module, is a layout system in CSS that provides a more efficient way to align, distribute space, and reorder content in containers even when their size is unknown or dynamic. It mainly focuses on typical one-dimensional layouts and controls the space distribution between items in an interface and the alignment of those items within the container.

When using Flexbox, you start by defining a flex container using the display: flex; or display: inline-flex; property on a parent element. This flex container turns all its direct children into flex items, and their layout can be easily manipulated with a set of Flexbox-specific properties.

How can you create a responsive navigation menu using HTML and CSS?

Creating a responsive navigation menu involves structuring your HTML correctly and using CSS for flexible styling, and often includes CSS media queries to ensure that the navigation adapts to various screen sizes. Here is a more detailed guide on how to achieve this:

• HTML Structure: Begin with a basic unordered list to define the navigation links.

<nav>

    <ul class="navigation">

        <li><a href="#">Home</a></li>

        <li><a href="#">About</a></li>

        <li><a href="#">Services</a></li>

        <li><a href="#">Contact</a></li>

    </ul>

</nav>

• CSS Styling: Start by styling your navigation to display as a horizontal menu using Flexbox.

.navigation {

    display: flex;

    justify-content: space-around;

    list-style: none;

    padding: 0;

.navigation a {

    text-decoration: none;

    color: #333;

    padding: 10px;

/* Adding a simple hover effect */

.navigation a:hover {

    color: #017cff;

• Media Queries for Responsiveness: Utilize media queries to adapt the layout for smaller screens, such as changing from a horizontal layout to a hamburger menu or vertical stacking.

@media (max-width: 768px) {

    .navigation {

        flex-direction: column;

This basic media query specifies that when the viewport width is less than or equal to 768 pixels, the navigation items should be stacked vertically.

• Advanced Interactivity: To enhance functionality, especially for touch devices, you can add JavaScript or CSS to handle menu toggling on smaller screens, such as implementing a hamburger menu icon that users can tap or click to expand the navigation options.

 Describe the purpose of the 'transition' property in CSS.

The 'transition' property in CSS is used to smoothly animate changes in element properties over a specified duration. It defines how a property change should transition from its initial state to its final state. This provides a visually pleasing effect when elements change their appearance.

How do you vertically align content using CSS?

Vertical alignment can be achieved using techniques like flexbox or positioning. To vertically center content using flexbox:

.container { display: flex; align-items: center; justify-content: center; height: 100vh; /* for full viewport height */ } 

What is the 'localStorage' API and how is it different from 'sessionStorage'?

'localStorage' is a web storage API in JavaScript that allows you to store key-value pairs in a web browser with no expiration time. Data stored in 'localStorage' persists even after the browser is closed and is accessible across sessions. 'sessionStorage' is similar, but the data is specific to a single session and is cleared when the session ends (browser closed).

How would you implement lazy loading for images on a website?

Lazy loading for images can be implemented using the 'loading' attribute in the 'img' tag. Setting 'loading="lazy"' tells the browser to load the image only when it's near the viewport. This improves initial page load performance by not loading off-screen images immediately.

Explain the purpose of the 'aria-' attributes in HTML for accessibility.

aria- (Accessible Rich Internet Applications) attributes are a set of special accessibility attributes in HTML that provide a means to communicate the roles, states, and properties of web content and interactive elements to assistive technology like screen readers. They are part of the Web Accessibility Initiative - Accessible Rich Internet Applications (WAI-ARIA or ARIA for short) specification from the World Wide Web Consortium (W3C), which is specifically designed to help with making web content more accessible to individuals with disabilities.

ARIA attributes are particularly useful in cases where traditional HTML elements may lack the necessary semantic meaning to convey their function or status. These include dynamic content and complex user interface components developed with Ajax, HTML, JavaScript, and related technologies.

How do you create a toggle button using only CSS?

A toggle button can be created using the :checked pseudo-class and the adjacent sibling selector ( + ) in combination with labels. Here's an example of a simple checkbox-based toggle button:

<input type="checkbox" id="toggle"> <label for="toggle" class="toggle-button"></label> 

.toggle-button { width: 50px; height: 30px; background-color: #ccc; display: inline-block; cursor: pointer; } #toggle:checked + .toggle-button { background-color: #66bb6a; } 

Describe the concept of event bubbling in JavaScript.

Event bubbling is a phenomenon in JavaScript where an event triggered on a nested element "bubbles up" through its parent elements in the DOM tree. This means that if you have a click event on a deeply nested element, the click event will also trigger on its parent elements, sequentially.

What are the benefits of using SVG (scalable vector graphics) over other image formats?

SVG is a vector graphics format that's resolution-independent and can be scaled without loss of quality. Unlike raster image formats (like PNG or JPEG), SVG images are code-based, making them smaller in file size and more flexible for animations and interactivity. They are also accessible, customizable with CSS, and easily indexable by search engines.

How can you create a simple slideshow using HTML, CSS, and JavaScript?

You can create a basic slideshow by structuring HTML with image elements and using CSS for styling. JavaScript can be used to control the slideshow by toggling image visibility or changing the 'src' attribute. Here's a simplified example:

<div class="slideshow"> <img src="image1.jpg" class="slide"> <img src="image2.jpg" class="slide"> <!-- More images --> </div> 

.slideshow { width: 100%; overflow: hidden; } .slide { width: 100%; height: auto; opacity: 0; transition: opacity 0.5s; } .slide.active { opacity: 1; } 

JavaScript:

const slides = document.querySelectorAll('.slide'); let currentIndex = 0; function showSlide(index) { slides.forEach((slide, i) => { if (i === index) { slide.classList.add('active'); } else { slide.classList.remove('active'); } }); } setInterval(() => { currentIndex = (currentIndex + 1) % slides.length; showSlide(currentIndex); }, 2000); 

Explain the 'pointer-events' property in CSS.

The 'pointer-events' property in CSS controls how an element responds to user interaction events like clicks and cursor interactions. It can be set to values like 'none', which makes the element completely unresponsive to events, or 'auto', which allows normal interaction. This property is useful when creating complex UI components or managing event interactions.

How do you create a responsive table that adjusts to different screen sizes?

Creating a responsive table involves ensuring that it remains legible and usable on devices of various sizes. CSS media queries are often used in conjunction with other CSS properties to adapt the table's layout for small screens. Here's a way to make a table responsive:

Basic Table HTML Structure:

<div class="table-responsive">

    <table>

        <thead>

            <tr>

                <th>Header 1</th>

                <th>Header 2</th>

                <!-- More headers -->

            </tr>

        </thead>

        <tbody>

                <td>Data 1</td>

                <td>Data 2</td>

                <!-- More data cells -->

            <!-- More rows -->

        </tbody>

    </table>

CSS Styling for Responsiveness: Use a containing div to handle the scrolling, and media queries to adjust styles:

.table-responsive {

    overflow-x: auto; /* Enable horizontal scrolling when necessary */

    width: 100%;

    border-collapse: collapse; /* Optional, for styling */

    border: 1px solid #ddd; /* Optional, for styling */

    text-align: left; /* Optional, for styling */

    padding: 8px; /* Optional, for styling */

/* Media query for small screens */

@media (max-width: 600px) {

    th, td {

        max-width: 100px; /* Set to a reasonable width */

        white-space: nowrap;

        overflow: hidden;

        text-overflow: ellipsis; /* Optional, to indicate text is clipped */

In the CSS above, the .table-responsive class is applied to a div that wraps the table. This div then handles any overflow on smaller screen widths by becoming scrollable. The media query ensures that on small screens, the cells do not expand beyond 100px and use white-space, overflow, and text-overflow properties to manage content that is too wide for the cell.

These styles create a horizontal scroll for the table on small screens, ensuring the content inside the table remains accessible without disrupting the layout of the page. It also provides a clean way to maintain readability by preventing data from overflowing the cells.

How can Web Components be used in front-end development, and what are the key specifications involved in creating them?

Web Components are a suite of different technologies allowing developers to create reusable custom elements encapsulating their functionality, outside the scope of the main document DOM. The key specifications for creating Web Components include Custom Elements (for defining new elements), Shadow DOM (for encapsulation), HTML Templates (<template> and <slot>), and ES Modules (for importing/exporting functionality).

<template id="my-custom-element">

  <style>

    /* Scoped CSS styles here */

      color: blue;

  </style>

  <p>My Web Component</p>

</template>

<script>

  class MyCustomElement extends HTMLElement {

    constructor() {

      super();

      let template = document.getElementById('my-custom-element').content;

      const shadowRoot = this.attachShadow({ mode: 'open' }).appendChild(template.cloneNode(true));

  customElements.define('my-custom-element', MyCustomElement);

</script>

How would you implement a 'sticky' footer at the bottom of a webpage?

A 'sticky' footer is a footer that sticks to the bottom of the viewport when the content is shorter than the viewport height but is pushed down by the content when it's taller than the viewport. Using Flexbox is an effective way to achieve this behavior. Here's a step-by-step approach:

HTML Structure:

<!DOCTYPE html>

<html lang="en">

<head>

<meta charset="UTF-8">

<meta name="viewport" content="width=device-width, initial-scale=1.0">

<title>Sticky Footer Example</title>

<link rel="stylesheet" href="styles.css">

</head>

<body>

    <div class="content"> 

        <!-- Main content goes here -->

    </div>

    <footer class="footer"> 

        <!-- Footer content goes here -->

    </footer>

</body>

</html>

CSS Styling with Flexbox:

    height: 100%; /* Ensure the full height for flex stretch */

    display: flex; /* Use Flexbox for body layout */

    flex-direction: column; /* Stack children vertically */

    min-height: 100vh; /* Minimum height as viewport height */

    margin: 0; /* Reset default margin */

    flex: 1; /* Flex value that allows to grow and shrink to fill available space */

    flex-shrink: 0; /* Footer should not shrink */

    background-color: #333; /* Footer color */

    color: white;

    padding: 20px;

    text-align: center;

In this CSS, the body is turned into a flex container with the direction of its items set to column, allowing you to stack .content and .footer vertically. The .content area is given a flex value of 1, which makes it grow to fill available space, pushing the footer down at the bottom if the content is not tall enough.

Describe the 'transform' property in CSS for 2D and 3D transformations.

The transform property in CSS allows you to apply various graphical transformations to HTML elements, altering their appearance and position without affecting the normal document flow. This differs from properties like position or margin, which can impact the layout of other elements.

For 2D transformations, you can use functions like 'translate()', 'rotate()', 'scale()', and 'skew()'. For 3D transformations, you can use functions like 'translate3d()', 'rotate3d()', and 'scale3d()'. These transformations enable visually appealing effects like scaling, rotation, and perspective changes.

How can you set a background image to cover the entire viewport using CSS?

You can set a background image to cover the entire viewport using the 'background-size' property with the value 'cover'. This scales the background image to cover the entire container without distorting its aspect ratio:

.container { background-image: url('image.jpg'); background-size: cover; background-repeat: no-repeat; background-position: center center; min-height: 100vh; } 

What's the purpose of the 'download' attribute in HTML anchor tags?

The download attribute in HTML <a> (anchor) tags instructs the browser to download the resource specified by the href attribute rather than navigating to it. This is particularly useful for creating download links to files that browsers can display, such as images or PDFs, which would ordinarily open within the browser window or tab.

When you use the download attribute, you can optionally assign it a value to define the filename for the file once it's downloaded, like so:

<a href="/files/example.pdf" download="NewFileName.pdf">Download PDF</a>

In this example, when the user clicks the link, the browser will download the file as "NewFileName.pdf" instead of navigating to it.

Explain the concept of memoization in JavaScript for performance optimization.

Memoization is an optimization technique used in JavaScript to increase the performance of computationally intensive functions. It works by caching the results of function calls based on their input parameters. Once the result of an operation is stored, future calls with the same arguments can quickly retrieve the cached result rather than recalculating it.

Here's how memoization can be implemented:

const memoize = (fn) => {

  const cache = {};

  return (...args) => {

    const stringifiedArgs = JSON.stringify(args);

    if (stringifiedArgs in cache) {

      return cache[stringifiedArgs];

    const result = fn(...args);

    cache[stringifiedArgs] = result;

    return result;

// Example function that calculates factorial

const factorial = memoize(

  (x) => {

    if (x === 0) {

      return 1;

    return x * factorial(x - 1);

In this example, we have a memoized version of a factorial function. The first time you call factorial with a specific argument, it calculates the result and stores it in the cache. The next time you call factorial with the same argument, it retrieves the result from the cache without performing the calculation again.

Wrapping up

Front-end development is an ever-evolving field that challenges both seasoned professionals and fresh faces in the industry to stay current with the latest technologies, best practices, and emerging trends. The questions and answers provided in this blog aim to give you a taste of the depth of knowledge required to excel as a front-end developer in 2024. 

For the developers, these insights are a way to gauge your learning curve, discover areas that need focus, and prepare for interviews with confidence. For the hiring managers, these questions help in identifying candidates who not only have the technical skills but also the critical thinking and problem-solving abilities necessary for creating cutting-edge web solutions.

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Front End Developer Interview Questions

The most important interview questions for Front End Developers, and how to answer them

Getting Started as a Front End Developer

• What is a Front End Developer
• How to Become
• Certifications
• Tools & Software
• LinkedIn Guide
• Interview Questions
• Work-Life Balance
• Professional Goals
• Resume Examples
• Cover Letter Examples

Interviewing as a Front End Developer

Types of questions to expect in a front end developer interview, technical proficiency questions, behavioral questions, design and ux questions, performance optimization questions, problem-solving and algorithm questions, project and code review questions, preparing for a front end developer interview, how to prepare for a front end developer interview.

• Understand the Company's Tech Stack: Research the specific technologies the company uses for front-end development. Familiarize yourself with their frameworks, libraries, and tools. This will help you to tailor your discussion to their stack and show that you can hit the ground running.
• Brush Up on Core Front-End Technologies: Ensure you have a strong grasp of HTML, CSS, and JavaScript, as these are the foundational technologies of front-end development. Be prepared to demonstrate your coding abilities and problem-solving skills in these areas.
• Review Frameworks and Libraries: If you know the company uses frameworks like React, Angular, or Vue.js, dive deep into their specifics. Understand the lifecycle methods, state management, and component architecture relevant to the framework.
• Practice Coding Challenges: Work on coding challenges, especially those that involve algorithms and data structures. Use platforms like LeetCode, HackerRank, or CodeSignal to sharpen your skills and speed.
• Prepare for Behavioral Questions: Reflect on your past projects and experiences. Be ready to discuss challenges you've faced, how you've worked with teams, and what you've learned from your successes and failures.
• Understand Responsive Design and Accessibility: Be prepared to discuss how you approach making websites accessible and responsive across different devices and browsers. Familiarize yourself with best practices and relevant guidelines like WCAG.
• Portfolio Review: Ensure your portfolio is up-to-date with your best work. Be ready to walk through your projects, explaining your design decisions, the technologies used, and any obstacles you overcame during development.
• Prepare Your Own Questions: Develop insightful questions about the company's front-end practices, the team structure, and the types of projects you would be working on. This shows your interest in the role and helps you assess if the company is the right fit for you.
• Mock Interviews: Practice with a mentor, friend, or use online resources to simulate the interview experience. This can help you get comfortable with the format and receive constructive feedback on your performance.

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Front End Developer Interview Questions and Answers

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Top 27 Front-End Developer Interview Questions (+ Answers)

When you’re hiring a Front-End Developer to join your team, how do you know you have the right person with the right skills for the job?

You need to start by asking the right Front-End Developer interview questions. ✅

In your next interview, come prepared with these unique interview questions to help identify your candidates’ potential strengths and struggles. A strong line of questioning will help you in your hiring process to enable you to find the best person for your engineering team.

Read on for the top interview questions, plus the types of answers you should be listening out for in an ideal Front-End hire.

<div class="inpage-callout-container"><p class="inpage-banner-text">💡 Remember: A job interview is a two-way street—your candidate is also interviewing you about what it is like to work at your company. They need to feel confident in their decision to join your team. Be ready to answer candidate questions and share information that’d get them excited about accepting an offer.</p></div> ‍

📣 Free Front-End Developer job description template to spark your candidates’ interest

General interview questions

Ask these general interview questions for Front-End Developers to get a better sense of their background, what they’re looking for in their next role and why they’re interested in joining your engineering team.

<h3 class="h3-small">1. What are you hoping to gain from your next role that you lacked in your previous role?</h3>

This question can help you gauge whether the candidate’s career aspirations align with your needs as a company. It will also help you gain a deeper understanding of their motivators which is an integral part of keeping team members happy and productive so they stick around for longer.

Listen for: What makes this person tick and what it will take to keep them around for the long haul. That could be money, growth opportunities or a passion for the work. It’s important to listen without judgment and try to meet them where they are at.

<h3 class="h3-small">2. Which of our company values do you most identify with and why?</h3>

A candidate who wants to work for your company will have done their research. This question allows you to find out how much and potentially spot someone genuinely interested in your work and what they admire most about your company.

Listen for: Someone who is particularly interested in your business’s future. People who are already thinking of ways to benefit your company are valuable assets.

📣 How to conduct a job interview candidates will write home about

<h3 class="h3-small">3. What’s the top strength you have that would make you a good fit for this role?</h3>

Ask this Front-End Developer interview question to get an idea if your potential hire has a strong understanding of what the role will require of them and if they believe they can do the job.

Listen for: Examples of strong communication skills, a collaborative spirit and leadership qualities. Their answer should also demonstrate their organizational skills and attention to detail.

📣 50 job application questions to get the right person for the job

<h3 class="h3-small">4. What do you see as being one of your most significant challenges in this role?</h3>

This interview question will give you insight into both what the candidate thinks they struggle most with at work and how they have overcome those challenges in the past.

Listen for: Someone who is transparent in their answer. Pay attention to how they overcome their challenges and limitations in the workplace, and how they put focus on this in their answer. Also, listen out for their adversity- and problem-solving skills.

<h3 class="h3-small">5. How do you maintain balance in your work and personal life?</h3>

You must know how your candidate maintains their focus and balance in their personal life and work. If they don’t have a proper answer to this question, they may be more prone to burnout.

Listen for : Things like resting, logging off at the end of the day and turning off notifications. Being able to take time off to recharge is the sign of a Front-End Developer candidate who values rest and recovery so they can bring their best selves to work.

<h3 class="h3-small">6. What kind of work environment do you do your best work in?</h3>

Ask this question to get a better idea of what type of environment your candidate might succeed in and consider if this is something your company can offer.

Listen for: There’s no right or wrong answer to this question — work environments are all about personal preference. The purpose of this question is to make sure you’re aligned with your candidate.

<h3 class="h3-small">7. What are you passionate about outside of work?</h3>

Remember there are no wrong answers here! This interview question aims to get to know your candidate better on a more personal level. It may be best for a second or third interview.

Listen for: Anything! You’ll want to hear a true sense of passion about anything they enjoy in their personal life.

Hard skills questions

You could always ask specific questions based on the various tools and coding a Front-End Developer might know. But apart from the more obvious, high-level technical questions, we recommend throwing in some of these questions in your next Front-End Developer interview.

<h3 class="h3-small">8. In your opinion, what are some of the most important skills you can have as a Front-End Developer?</h3>

There are many different hard skills that a Front-End Developer needs to be successful in their role. This interview question will help you gain an understanding of your candidate's knowledge of the job and what it entails.

Listen for: Strong attention to detail, a sense of visual design, and proficiency in coding languages like HTML, CSS and JavaScript. Additionally, you want to identify their skills in testing and debugging.

<h3 class="h3-small">9. How do you stay up to date on industry trends?</h3>

With this Front-End Developer interview question, you’ll get a feel for your candidate’s involvement in technology and continuous learning.

Listen for: Any mentions of their favorite forums or webinars for gaining industry insider knowledge. Additionally, they may enjoy taking on unique or personal projects to develop their skills.

📣 Hiring remotely? Check out these interview questions for hiring remote employees

<h3 class="h3-small">10. Tell us about a project that you worked on developing. What tools did you choose to use and why?</h3>

The answer to this question should give you some insight into the methodology of your candidate as a Front-End Developer. They should demonstrate a strong knowledge of the tools of the trade.

Listen for: The specific tools that they used for the project. They should also display an in-depth knowledge of the tools and explain why they were the best for the job.

<h3 class="h3-small">11. What is the most challenging programming problem you’ve dealt with recently?</h3>

For a Front-End Developer, there will always be challenges requiring creative problem-solving measures. You need to be sure that your candidate has the analytical skills to handle those challenges professionally.

Listen for: A demonstrated aptitude for collaboration and problem-solving in their answer. Make sure they provide specifics when speaking about how they overcame the challenge. If they don’t, ask a follow-up question.

<h3 class="h3-small">12. How do you ensure your code is clean and your documentation is thorough?</h3>

This hard skills interview question helps you understand your candidate’s approach to coding and how they stay organized. In software development, it’s key to be able to understand what another Developer who worked with the code did.

Listen for: If they see the value in being able to communicate clearly with the next person who’s working on the code.

📣 A Guide to Diversity, Equity & Inclusion in the workplace

<h3 class="h3-small">13. Do you have any coding projects on the go?</h3>

Someone passionate about technology and growing their skill set will almost always have a project they are willing to share. Find out about what they’ve learned from the project thus far and also get an idea of how much they love to code!

Listen for: Proficiency in coding and any takeaways that they have from their project at this point. If the project is unfinished, ask them about the end goal and how they plan to get there.

Organize all your job interviews in one place with Homerun.

Soft skills questions

While you might be looking for a Developer with all the skills and abilities necessary to get the job done, you also need candidates with the attributes required to work productively and harmoniously with other folks on your team. 🕊️

<h3 class="h3-small">14. How do you collaborate with people who have varied personality types?</h3>

This question will help you establish if your candidate is going to be able to work well with your team. Working in a collaborative environment requires shared mutual respect amongst everyone.

Listen for: Talk of communication, mutual respect, teamwork and participation. Your candidate should display a sense of empathy, patience and openness.

<h3 class="h3-small">15. How do you feel about getting constructive feedback and how do you handle it?</h3>

Feedback is a vital part of anyone’s professional growth and development. As an employer, you need to know that your candidate will be able to embrace any constructive feedback in a productive way.

Listen for: Someone who can speak of feedback as an opportunity for growth and development. They can both receive and deliver feedback professionally and positively.

<h3 class="h3-small">16. How do you relay important information to your team?</h3>

How does your candidate pass along key information during busy times? You’ll want to know they understand the importance of this and that they have the skills necessary to communicate effectively and efficiently.

Listen for: A clear and concise communication style with their answer. Additionally, their response should indicate a willingness to provide follow-up clarification.

<h3 class="h3-small">17. How do you handle conflict within your team?</h3>

It’s only natural that conflict amongst team members will happen. When it does, it must get resolved quickly. The end goal should also be to avoid demoralizing the rest of the team when conflict does arise.

Listen for: Your candidate’s ability to de-escalate a situation. Pay close attention to their conflict resolution skills.

<h3 class="h3-small">18. How do you stay organized when managing multiple projects?</h3>

With their answer, your candidate should display prioritization and multi-tasking skills. Additionally, they should be able to identify tools or techniques they go to often to stay organized in their Front-End work.

Listen for: How they prioritize their workload, manage time and if they delegate work to other team members or if they work independently.

<h3 class="h3-small">19. How do you minimize distractions during the workday?</h3>

Remote or in-office, distractions at work are nothing new. In a sense, they’re unavoidable. How your candidate acknowledges this struggle and the tactics they use to avoid distractions matters.

Listen for: Various tactics they rely on to avoid getting distracted: taking regular breaks, setting boundaries, rewarding themselves or breaking down large tasks into small, bite-sized tasks.

Behavioral interview questions

Behavioral interview questions are all about asking candidates for examples of how they’ve handled certain situations. Listen carefully to their answers and be sure to ask follow-up questions if you need more information. These questions help you uncover how your candidate might behave in specific, future scenarios.

<h3 class="h3-small">20. Can you tell me about a time when you went above and beyond to solve a problem at work?</h3>

While it’s essential for people to maintain healthy boundaries to protect their work-life balance, occasionally, the job might require experience navigating tasks and situations that aren’t necessarily part of the job description. This question will help you assess those abilities.

Listen for: A real-world scenario. You want to hear that they displayed sound judgment, applied logic to the situation and collaborated with their team to resolve the problem.

📣 Ready to kickstart your hiring? Check out the best recruiting software for small businesses

<h3 class="h3-small">21. What do you do when a team member is having a bad day?</h3>

You want to understand how your candidate will be affected by the moods of others. You also want to see what this person would do to help improve the situation, like checking in with the team member and keeping the rest of their team on track to reach their goals.

Listen for: Behaviors that will help contain and defuse negativity within the group. Someone who can approach a situation like this with empathy, reasoning, calm and understanding will be an ideal addition to your team.

<h3 class="h3-small">22. Tell me about a work accomplishment you’re most proud of.</h3>

This is your candidate's chance to brag and demonstrate their abilities. It will give you a glimpse into their personality, passion and dedication to their work.

Listen for: Excitement or pride as they talk about their accomplishments. Listen out for what motivates them and consider if you as an employer can meet that motivational need.

<h3 class="h3-small">23. Has there ever been a time when your outside-the-box thinking helped solve a problem?</h3>

Sometimes a problem requires a different way of thinking. You want your candidate to have the ability to see issues from different angles and develop creative solutions to overcome challenges.

Listen for: Behaviors that display creativity, adaptability and solution-based action.

<h3 class="h3-small">24. If your colleagues could describe you in three words, what would they be?</h3>

The words they pick can say much more about a person than you might think. It gives you additional insight into what their soft skills are, how they collaborate on a team and how they approach work.

Listen for: Words that would describe the ideal candidate for the open role, like “adaptable,” “patient”, “flexible” and “collaborative.”

<h3 class="h3-small">25. What do you do when you feel overwhelmed by the tasks on your to-do list?</h3>

For Front-End Developers (and any team member!), it’s normal to feel stressed and overwhelmed once in a while by to-do list priorities. What’s important to look for in a candidate is someone who acknowledges that this can happen and has ways they combat it so that they feel balanced and healthy.

Listen for: Task prioritization. They may have some unique tactics they use to prioritize competing tasks. They should mention delegating and asking for help when they need it. The right candidate should be able to admit when they need help!

<h3 class="h3-small">26. Can you tell me about a time you made a mistake at work?</h3>

As we learned on Sesame Street , everyone makes mistakes! This isn’t a “gotcha” question.  The goal of this Front-End Developer interview question isn’t to highlight a candidate’s flaws or errors, but to hear how they acknowledge previous mistakes, what they learned from them and how they resolved them.

Listen for: A sense of self-awareness that no one is perfect. They should also share the lessons they took away from this experience and how they came up with a solution (if a solution was possible!).

<h3 class="h3-small">27. What’s the most valuable feedback you’ve received?

Ask this interview question to hear what kind of constructive feedback has helped your candidate the most in their career or even in their personal life.

Listen for : A real-life scenario and how they took on this feedback to improve themselves. Their answer doesn’t have to be limited to a workplace example — feedback from their personal life may also be incredibly relevant and enlightening for you as an interviewer!

Hire your next Front-End Developer with Homerun

There are a lot of Front-End Developers out there, and evaluating whether a certain candidate is right for your team is less than simple.

On top of finding a good fit, you also have the entire hiring process to worry about. You need to organize your hiring pipeline, get the rest of your team involved and provide potential hires with a positive candidate experience. All while making sure you recruit and hire the right person with the right skills.

That’s where hiring software comes in.

Homerun helps you organize and streamline your entire hiring workflow, and make a good impression with Developer candidates while you’re at it. Once you get past the job application stage, you can involve the rest of your team: share feedback on the candidates, get a visual of the hiring workflow, email candidates, invite them to final interviews, share Front-End coding exercises and keep everything organized in one place.

Improve your hiring and interview workflow so you can focus on hiring your next Front-End Developer.

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Front end developer interview questions, download pdf.

Front-end development is regarded as one of the most successful fields, particularly for novices in web development. Owing to the fact that it needs primarily basic skills like HTML, CSS, JavaScript, and a bit of server knowledge, many beginners consider front-end development to be a good way to start a career in full-stack development . Nevertheless, the field of front-end development is comprehensive and encompasses multiple different techniques and tools. Hence, interview questions for the position of front-end developers are diverse in nature and span across different domains.  

In the world of technology, a programmer should be devoted to coding and efficient enough to transform the client’s requirements into the application. In any front-end developer interview, the interviewer looks for this type of enthusiasm in the candidates. It is a well-known fact that the topmost IT firms are looking to employ front-end developers who are liable to build and manage interactive and responsive applications for all the devices by upholding client convenience and simplicity in mind.

If you are looking for a front-end programmer's job and don’t have any idea how to get ready for the interview, you should not be worried as this article throws light on all the complicated and confusing questions that interviewers are more likely to ask you. These questions would give you a better picture of what employers want you to know. The interview questions for both freshers and experienced individuals are discussed here.

What is front-end development?

Frontend development denotes the realm of web development that concentrates on what the users see on their end. It revolves around changing the code created by backend developers into a graphical interface, making sure that the data is delivered in a simple, easy-to-read format. Without frontend development, all one can see on a website or web application would be some undecipherable codes. Because of frontend developers, people having no background in coding can readily understand and utilize web applications and websites. The thing you see when you visit Canva, Facebook, Google Apps, and other web applications are products of both frontend and backend developers working together.

Other than assuring that users can understand and effectively utilize the web application's graphical interface, front-end developers also have many other things on their plates. For instance, frontend developers must look into the fact whether the web application or website is functional across different devices. Take note that systems differ in terms of operating system (OS) and screen size. A user can own a Windows tablet, a MacBook, and an Android mobile phone. Regardless of device type and OS, it is the job of the frontend developer job to make sure that the applications or websites work. Frontend developers are that users may prefer different web browsers. Also, frontend developers must build a website carefully that functions on Mozilla Firefox, Chrome, Safari, Microsoft Edge, Internet Explorer, and Opera. 

Front End Developer Interview Questions for Freshers

1. what skills does a front-end developer need.

Frontend developers utilize different web technologies to change coded data into user-friendly interfaces. Many among these are Cascading Style Sheets (CSS), JavaScript, HyperText Markup Language (HTML), etc. Mentioned below are brief explanations of these technologies that frontend developers must be acquainted with.

• HTML: HyperText Markup Language depicts the content on the page like buttons, links, headings, paragraphs, and lists. It is the building block of websites and is utilized to define and mark content, so a browser shows it correctly. For instance, on a blog post, an image can be seen as an <img> in HTML code, so browsers will understand that they have to display an image.
• CSS: CSS stands for Cascading Style Sheets and is accountable for the style of your web pages such as animations., colours, and layouts. CSS appears more like a group of instructions that gives structure and style to a webpage than a programming language. It enables programmers to control a web application or website's layout, formatting, and presentation. While HTML depicts elements on a page, CSS is accountable for how users see the content. For instance, it handles the border, alignment, size, of an image in a blog post.
• JavaScript: JavaScript is one of three main elements, in front-end web development, that is required to end up with a web page that can be rendered accurately. It is now challenging to visualize websites without JavaScript as it allows programmers to make the sites interactive. This programming language can transform website content on the basis of a user’s action. For instance, at the top of the page, when you click on the Menu button, it will display a dropdown list of options or when you click on a button, it will toggle back and forth between closing and opening the Menu. JavaScript is great at figuring out the kind of browser being utilised, and then rendering the page in such a way that it is not only compatible with that page, but that it works the way it is designed. Using plugins is made easier by JavaScript. When complicated dynamic interactions are required for a site, JavaScript can be implemented to design its framework instead of simply depending only on HTML.
• CSS Frameworks, Libraries, and Preprocessors: Once you understand the fundamentals of CSS, then you can begin to work with various libraries and frameworks. These tools were designed as a way to help hasten the development process. Frameworks like Tailwind CSS, and Bootstrap let you incorporate the catalogue of classes into your webpage. Hence, you end up with mobile-friendly and professional designs. There are ample choices on the market and you don't require to know them all. It's often useful to look at related jobs and check what technologies they're employing. Then you can concentrate on the most in-demand skills.
• Testing and Debugging skills: As you are creating your application, there will be mistakes in your code that require to be fixed. Debugging is the act of recognizing those bugs and resolving them. Another essential skill to know is debugging. Documenting tests for your code is a way to assure that your code is accomplishing what it is meant to do.
• Version control: The way of tracking and the modifications to the project's code is version control. Git is regarded as a popular software that is utilized to track your code. If your code gets messed up, you can utilize Git to go back to an earlier version of your code rather than manually rewriting everything. Learning Git also lets you cooperate with others on a team and make modifications to the same code base from various locations. It is advised that you should start to learn Git and use a service like GitHub to host your projects.

2. Define HTML meta tags.

• Meta tags are passed as pairs of name/value.
• Meta tags can include data about encoding, document title, character description, etc,
• Meta tags fit inside the HTML page’s head tag.
• Meta tags are not displayed on the page but it is to be shown on the browser.

3. Differentiate between div and span?

4. what is react js.

An open-source front-end JavaScript library, ReactJS is used primarily for building user interfaces, especially for one-page applications. Also, it is utilized for handling the view layer for web and mobile apps. React lets programmers build large web applications that can modify data, without the need to reload the page. The main objective of React is to be quick, scalable, and easy. It functions only on user interfaces in the application and corresponds to the view in the MVC template. It can be utilized with a combination of other JavaScript frameworks or libraries, like Angular JS in MVC.

5. Describe the advantages of REST web services?

 Listed below are some of the advantages of REST web services :

• The curve of learning is simple since it works on the HTTP protocol.
• No contract clears between server and client, so roughly coupled application.
• REST approaches can be effortlessly tested on the browser.
• It also backs multiple technologies for the transfer of, for instance, image, JSON, XML, text, etc.
• It is a lightweight protocol.
• Software Dev
• Data Science

6. How browsers render the UI?

The primary responsibility of the rendering engine is to highlight the requested page on the browser’s screen. Rendering engines can show XML and HTML images and documents. If you’re utilising additional plugins, the engines can also exhibit various documents like PDF.

• Receives the requested document: The contents of the requested document is obtained by the rendering engine from HTML’s networking layer.
• Construct the DOM tree: Parsed the HTML to the parsed tree and then set up the DOM tree, making use of it.
• Construct the CSSOM: CSSOM stands for CSS Object Model. Post the construction of the DOM tree, it identifies a link tag in the head section, which references the external style.css CSS style sheet. So, it parsed the CSS file in CSSOM tree, something which the Browser can comprehend as the DOM tree.
• Construct the Render tree: Utilise the HTML DOM tree coupled with the styling data of the CSSOM tree to set up a render tree. Render tree is the graphical depiction of the HTML, with the corresponding CSS. This tree enables painting the contents in their right order. Every node in the Render Tree is regarded as a renderer. The Render tree looks like this:
• Layout: When the renderer is developed and incorporated into the tree, it does not have a size or position. Computing these values is defined as layout. We use the coordinates system to position the element, such as the position of the root renderer is 0,0. The layout continues recursively via a part of the entire renderer hierarchy, calculating geometric info for every renderer that needs it. Beginning the layout process implies allowing every node the exact coordinates where it should show up on the screen.
• Painting of the Render Tree: The renderer tree is traversed in this stage and the renderer’s paint() method is hailed to exhibit the content on the screen. For good UX, the rendering engine will aim to exhibit the contents on the screen as soon as possible. It will not stand by until all the HTML is parsed to develop and layout the render tree.

7. What is a Grid system in CSS?

CSS splits the page into grids and utilizes those grids to handle the HTML content. Utilizing the Grids, CSS can stack and highlight various elements in different parts of the grids.

8. Describe the distinction between Class and Prototypal inheritance in Javascript?

From most other programming languages, Inheritance in JavaScript is different. JavaScript's object system is prototype-based, not class-based. Objects in JavaScript are just a set of value pairs and a name (key). Talking about inheritance, JavaScript just has one construct: objects. Each object has a private property that includes a link to another object named its prototype.

9. Explain user-centered design?

An iterative design procedure, User-centred design lets the designers focus on the clients and their needs in every design process phase. The user-centered design calls for linking users in the design process via a variability of design and research techniques to make usable and highly accessible products. User-centered design demands that designers should utilize a combination of generative (such as brainstorming) and investigative (interviews and surveys) methods and instruments to create an understanding of user requirements.

10. What is ClickJacking?

ClickJacking is a security attack where the user is fooled to click on something while they assume they are clicking another thing. The attack mostly happens by the HTML frames. ClickJacking is also regarded as the user interface redressing. It lets the user think that they are utilising a normal UI in the web page, but in actuality, there is an unseen UI in control; you can think of it as the user interface being redressed. When users click on one thing, assuming it to be secure and safe, the hidden UI executes another action.

11. Tell me when and why should I make use of Webpack?

While creating a complicated front-end application with tons of non-code static possessions, for instance, CSS, fonts, images, etc, then, of course, you should make use of Webpack since it has a lot of amazing benefits.

If you have a small application that doesn't have a lot of static resources and you only have to create one file of JavaScript to help the customers, then Webpack should be more overhead than needed.

12. Mention three ways to decrease page load time?

There are numerous things accountable for lowering page load time. Let us look at the three best ways to reduce its loading time:

• Image Optimization: It is always advised to scale your videos and pictures before uploading them to a page.
• Browser Cache: The utilization of cache will boost speed for pages that you have visited already.
• Optimize and compress content: Compressing the content of a website decreases the load time of a page to a great extent.
• StyleSheet Reference on Top: Setting stylesheet reference to the header of a doc allows your page to load quickly.

13. How does the server hanger the page in which content is present in several languages?

When an HTTP request is sent to the server by the user, the user browser also sends a chunk of additional information regarding the language preference as the Accept-Language header. Then the server reads the HTTP request with the Accept-Language header and sends the document version back along with the right language and declares the language attribute Lang in the HTML tag.

14. Why did we utilize the data- the attribute in HTML and why it is now advised not to use?

Generally, Data-* attributes of HTML are utilized to accumulate the custom data, which is private to the web application or page. This custom data is for personalizing the JavaScript of the user as per the user action on the web page.

These days, Data-*attributes are not advised to utilize as the user can change the attribute easily just by utilizing the browser inspect console.

15. Mention the benefits of CoffeeScript over JavaScript?

• Write less do more − For a huge code in JavaScript, we require comparatively a very less number of lines of CoffeeScript.
• Easily understandable − The shorthand form of JavaScript is CoffeeScript, its syntax is quite simple as compared to JavaScript. Making use of CoffeeScript, we can document clean, clear, and easily discernible codes.
• Reliable − CoffeeScript is a secure and reliable programming language to create dynamic programs.
• Readable and maintainable − CoffeeScript offers aliases for most of the operators, making the code readable. Also maintaining the programs written in CoffeeScript is effortless.
• Class-based inheritance − JavaScript does not have classes, in place of them, it offers powerful but complicated prototypes. Unlike JavaScript, in CoffeeScript, we can make classes and inherit them. Additionally, it also provides instant and static properties along with mixins. It utilizes JavaScript's native prototype to construct classes.
• No var keyword − There is no requirement to utilize the var keyword to form a variable in CoffeeScript, hence we can evade accidental or undesirable scope deceleration.
• Avoids problematic symbols − There is no requirement to utilize the problematic parenthesis and semicolons in CoffeeScript. In place of curly braces, we can utilize whitespaces to distinguish the block codes such as functions, loops, etc.
• Extensive library support − In CoffeeScript, we can utilize the JavaScript libraries and vice versa. Thus, we have access to a myriad set of libraries while operating with CoffeeScript.

Front End Developer Interview Questions for Experienced

1. what is stringify.

IN a JSON method, stringify is used to transform a JavaScript object into a string. JSON is a common structure to receive and send data between the web server and the client, and when we wish to send data to the webserver, the object ought to be a string.

2. State all the elements of the CSS Box Model.

In its BOX model, CSS comprises 4 elements:

• Content – Displays the main content and the text of the web page.
• Padding – This area encircles the content.
• Border – The border is the padding's outer layer.
• Margin – Margin is the area outside the border.

3. What is Progressive Rendering?

Progressive rendering is a process that is utilized generally to boost the web page's rendering content process. Now the rendering process is utilized in modern web development to enhance the mobile data uses of the user, async HTML fragments, prioritizing visible content, and lazy loading of images.

4. In an image tag, what is the benefit of the srcset attribute?

srcset is utilized when we wish to generate several resolutions of the exact image on several devices. This improves the UI. The browser will display low resolution on low-end devices, and high resolution of an image on high-end devices.

5. Mention the difference between MySQL and MongoDB?

• MySQL: It is a Relational Database Management System (RDBMS), which makes use of SQL as a standard language to handle its database. Like different relational database management systems, MySQL makes use of a table-like structure to stow data.
• MongoDB: MongoDB is a NoSQL database that utilizes the JSON-like structure to stow data elements. To modify and access data in MongoDB, the programmer ought to make use of the MongoDB Query Language (MQL).

6. Define the Anonymous function in JS?

Generally, the function name is defined when we define the function itself, in normal user-defined functions, but in the case of an anonymous function, the function name is not defined. Here we make use of an assignment operator and variable to stow the function as an object, then utilizing that variable, we will be capable to invoke the function itself.

7. What do you know about the CSS image sprites and why it is utilized?

CSS image sprites assist to render numerous images in a single line image. In a nutshell, the CSS sprites merge numerous photos into a single large image. If a web page comprises different images, then it would raise its loading time as for every image the browser has to send a distinct HTTP request, but with the help of sprites, we have a single image to request.

8. Suggest some ways on how to fix the browser-specific styling issue?

• We can make a distinctive stylesheet for various browsers making use of server-side rendering.
• Another method is utilizing a library such as Bootstrap, which already has the code to manage the browser-specific styling issue.
• Reset or Normalize CSS can also be utilized. Multiple 3rd party plugins equip libraries for browser styling issues.

9. Mention the pitfalls for using a CSS Preprocessor like Sass?

• An extra tool for the preprocessor is required.
• Preprocessor files can not be performed directly on the browser.
• Slow re-compilation of the preprocessor.
• For the preprocessor, you ought to know extra tools, which improve the learning curve of CSS.

10. Suggest how can we optimize our front-end page.

• The consumption of resources can be reduced by the pages by enhancing the server response.
• Utilize JavaScript and External CSS instead of internal or in-line.
• Utilize the framework to ensure the front-end becomes more responsive to different devices.
• Open-source libraries can be used to manage the browser-specific styling issue.
• Make use of progressive loading like Lazy Loading to enhance the rendering of heavy elements, like videos and images.
• Connect the style sheet in the header and script at the top of the HTML's body tag.
• Utilize browser storage to keep user-specific private data.

11. What is the difference between attribute and property?

Attributes are an element of an HTML document while properties are a part of the Document Object Model (DOM).

Example: <input type="text" value="Tech">

Here, value and type are the attributes of HTML, but when the statement is read by the browser and parses this code it will make a DOM with different properties, like accept, autofocus, accessKey, baseURI, checked, childElementCount, align, alt, childNodes, children, classList, className, attributes, and clientHeight.

12. State the difference between == and ===?

  == denotes abstract equality operator, and it inspects if two values are equal or not apart from their data types. Automatically, it transforms the type of both the operands and compares them.

=== denotes identity equality operator, and it inspects the values of both the operands and their data type. The outcome of the operation will be true considering both the operands are equal and have the same data type, or else it returns false.

13. Why do we utilize the “use strict”; statement?

The ‘use strict’ statement sets a few restrictions in the script. Typically, it is utilized to facilitate the strict mode of the script, making sure there could be no loose coupling like undeclared variables.

14. Name the major HTTP requests

Additional useful resources.

• Front End Developer Salary in India – For Freshers & Experienced
• Front-End Developer Resume Sample (PDF): Full Guide and Example
• Best Front End Frameworks
• Difference Between Frontend and Backend – Frontend Vs Backend
• ​​​​Software Developer Vs Software Engineer

Frequently Asked Questions

1. how do i prepare for a front-end developer interview.

When you're preparing for your Front-end developer interview, try to code most of your layout without taking a glance at the result till the end. If CSS, HTMLare the most important aspect of front-end development, then JavaScript tops the list of important skills to own. Organisations will spend a lot of time during your interview to test your understanding of Javascript.

2. Why should we hire you as frontend developer?

• Freshers:  While interviewing for front-end developer jobs for freshers you can come across this question. The best answer would be, " I have just begun my career, and do not have practical achievements, but I wish to explore and experience my potential by giving the best services to the company. It will be my privilege to work with your organization."
• Experienced: The best answer would be, “ You should hire me for the role of front-end developer owing to my proven ability to create effective front-end user interfaces in line with contemporary best practices. I have experience working with JavaScript, along with the React framework, to create front-end applications.”

3. What is the most challenging work you have ever done as a front-end developer?

The biggest challenges faced as a front-end developer are:

• Make sure each UI element like button, link navigation,  works as planned despite the user having JavaScript or cookies disabled.
• Make sure everything looks similar across all browsers.
• HTML tables.
• Debugging JavaScript code.

4. How much do front end developers get paid?

As per the payscale, freshes, front-end developer gets an average of ₹305,498 per annum. An intermediate developer's salary is ₹452,073 on average. A senior developer can earn an average of ₹806,231.

5. Is front end developer a good career?

 Yes, a front-end developer is regarded as a good career choice. It is in demand by top-tier players like Deloitte, Amazon, HCL, etc. Furthermore, the annual pay for a front-end developer is lucrative. In a nutshell, it is an in-demand position, good pay, and new learning each day.

6. What is front end and back end web development?

Front-end development is considered as the programming which concentrates on the visual elements of an app or website that a user will interact with. Back end development concentrates on the side of a website that the user can't see, meaning the server-side.

7. Which language is best for front end development?

The languages best for front-end development are HyperText Markup Language (HTML), Cascading Style Sheets (CSS), JavaScript, React, Angular, Vue.

Front End Development MCQ Questions

Adding the style attributes in HTML elements is regarded to be:

Which attribute is utilised to link the bookmark?

A TARGET value that is utilized when a webpage is locked in a frame, is called?

During styling, making use of a <style> element in the head section is called

In HTML elements, CSS can be added in how many ways

Is it right to pass an unknown function as an argument to another function?

What is the purpose of an Array object that removes or adds elements from an array?

Which of the following processes clears the last element from an array and returns that element?

Which function of the Number object would show output in exponential format?

Which String object functions return the capitalized string while respecting the current locale?

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1 Million +

Top Front End Developer Interview Questions with Example Answers [2022]

Prepare for your front end developer interview by going through these most asked front end developer interview questions. additionally, get access to sample answers and interviewer's expectations..

Search Front End Developer Questions:

• Question: What happens when the user enters a URL?

Question Overview: This question tests the applicant's knowledge of the HTTP protocol. It's a basic question that can help you determine whether the person you're interviewing has a solid grasp of the basics of web development.

Sample Answer: The user enters a URL into their browser and the browser sends a request to the server hosting the website. The server then sends back a response that includes the HTML for the page. The browser then renders the page based on this HTML.

• - Detailed explanation of the process
• - Examples of how the applicant uses this knowledge in their work
• - Confidence in explaining this process to any audience
• Question: How do you keep up with new technologies?

Question Overview: Front end developers need to stay on top of the latest trends in web design and development. This question gives you insight into how they keep themselves informed about the latest developments in their field.

Sample Answer: I subscribe to several blogs and newsletters that cover the latest developments in web design and development. I also attend conferences and meetups to learn more about the latest trends.

• - A list of resources that the applicant uses to stay up-to-date
• - A history of staying up-to-date with new technologies
• - A willingness to learn new things
• Question: How will you differentiate between == and ===?

Question Overview: This question tests the applicant's knowledge of the JavaScript language and their ability to spot the difference between two similar operators.

Sample Answer: === is a strict comparison operator that evaluates both operands and returns true if they're equal. == is a loose comparison operator that evaluates both operands and returns true if they're equal. I use === when I'm comparing objects or numbers for equality.

• - A clear explanation of the difference between these two operators
• - An example of when to use each operator
• - Confidence in explaining this technical concept to any audience
• Question: What is CSS float property and how does it work?

Question Overview: This question tests the applicant's knowledge of CSS properties. It's a basic question that helps you determine whether the person you're interviewing has a strong grasp of CSS fundamentals.

Sample Answer: A CSS float tells the browser to put a particular element to the right side or the left side of the container. I use floats when I'm developing a page that dynamically resizes based on the user resolution.

• - A basic definition of CSS float
• - An explanation of how this property works
• - A demonstration of how the applicant uses this property in their code
• Question: What are the 3 most important languages for front end web development?

Question Overview: This question gives you insight into the applicant's knowledge of the most common languages used for front end development.

Sample Answer: HTML, CSS, and JavaScript are the three most important languages for front end web development. I use these languages on a daily basis to create web applications and pages.

• - First-hand experience with the 3 languages
• - Knowledge of the most important languages for front end development
• - A list of other languages that the applicant uses
• Question: Why do you want to work for us?

Question Overview: This question gives you insight into the applicant's interest in the company and their desire to work there.

Sample Answer: I've been a fan of your company for a long time, and I'm excited to get the chance to work here. I think my skillset will be a great fit for your team.

• - A clear explanation of why the applicant wants to work for your company
• - A clear explanation of how they fit into the company's mission
• - A desire to work for your company
• Question: What has been the most challenging project you have worked on so far?

Question Overview: This question gives you an idea of how the applicant handles difficult projects. It also gives you insight into their past work experience and how they've dealt with problems in the past.

Sample Answer: The most challenging project I worked on was a website redesign for a large company. I had to work with a team of developers and designers to create a new design that met all of our client's requirements.

• - A description of the most challenging project
• - How the applicant handled the challenge
• - A description of what they learned from the project
• Question: What do you like to code?

Question Overview: This question gives you an idea of what the applicant is interested in and what they're passionate about. It's a good way to see whether they're interested in the job you're offering.

Sample Answer: I like to code in JavaScript and HTML5. I also enjoy using Bootstrap for web page layouts.

• - A list of the applicant's favorite programming languages
• - Their favorite web frameworks
• - A list of their favorite development tools
• Question: How would you describe the setState method on a React component?

Question Overview: This question tests the applicant's knowledge of React, a popular JavaScript library for building user interfaces.

Sample Answer: The setState method updates a React component's state. I use this method to change the state of a component when a user interacts with it.

• - A clear definition of the setState method
• - Examples of how the applicant uses this method in their code
• Question: Have you worked on an API?

Question Overview: Front end developers often work on applications that are powered by an API. This question gives you an idea of whether the applicant has experience with this type of project.

Sample Answer: I worked on a project that used an API to pull data from a third-party service. I had to make sure that the application was able to handle large amounts of data and that the data was properly formatted.

• - Examples of API-powered projects
• - Knowledge of how to work with an API
• - Understanding of how to integrate an API into a web application
• Question: What is your experience with front end development?

Question Overview: This question gives you an idea of the applicant's experience with front end development. It's a good way to screen the interviewee and ensure that they're familiar with the basics of this role.

Sample Answer: I've worked on a number of web applications and sites that use HTML, CSS, and JavaScript. I've also worked on a few mobile applications using Xcode and Swift.

• - A list of front end development projects
• - A description of the applicant's role in these projects
• - A list of technologies used in these projects
• Question: How will you pass arguments to JS functions?

Question Overview: This question tests the applicant's understanding of JavaScript and how it handles arguments.

Sample Answer: I pass arguments to JavaScript functions by using the function name as a variable. For example, I might have a function called "showAlert" and pass the message to show as an argument.

• - A clear explanation of how the applicant passes arguments to JS functions
• - Examples of how they pass arguments to JS functions
• Question: How do you know about the lifecycles of react?

Question Overview: React is a popular JavaScript library that's used for building user interfaces. This question gives you an idea of the applicant's experience with this library.

Sample Answer: I use the componentWillMount method to load data from a remote server and store it in a variable. I use componentDidMount to display this data on the page.

• - Knowledge of the lifecycle methods
• - Examples of how the applicant has used these methods in their code
• - Confidence in explaining these methods to any audience
• Question: How did you get into web development?

Question Overview: This question gives you insight into the applicant's background and how they got into the field. It's a good way to see whether they're passionate about the industry and whether they have a solid foundation for their current position.

Sample Answer: I first got into web development when I was in high school. I was a big fan of the internet and wanted to learn how to build my own websites. I started with HTML and CSS and then moved on to JavaScript and PHP.

• - A history of working with computers
• - A history of working with web technologies
• - A history of working with web development tools
• Question: What is the project you are most proud of?

Question Overview: This question gives you insight into the applicant's past work and what they're most proud of. You can use this information to determine whether they're a good fit for your company.

Sample Answer: I'm most proud of my work on a website for a non-profit organization. I worked with a team of developers to create a site that was easy to navigate and provided information about the organization's programs and services.

• - A project that shows the applicant's skills and experience
• - A project that shows the applicant's creativity and problem-solving abilities
• - A project that shows the applicant's ability to work within a team
• Question: What kind of work environment do you prefer?

Question Overview: This question gives you insight into the applicant's personality and work ethic. It's important to hire people who are interested in working in a collaborative environment.

Sample Answer: I prefer to work in a quiet environment with minimal distractions. I like to focus on my work and don't like to be interrupted. I also like to work from home on the weekends so I can spend time with my family.

• - The applicant's preferred work environment
• - The applicant's preferred work style
• - The applicant's preferred work schedule
• Question: How will you differentiate between call() and apply()?

Question Overview: This question tests the applicant's knowledge of JavaScript functions. It's a good way to see whether they have a strong understanding of the language and can apply it to real-world problems.

Sample Answer: The call() function takes a JavaScript object and calls a function on it. The apply() function takes an array of objects and calls a function on each one. I use call() when I want to pass an object to a function and apply() when I want to pass an array of objects to a function.

• - A clear explanation of the difference between call() and apply()
• - Examples of when the applicant has used these functions
• Question: Write a program that reads in JSON file, translate it and display the results in a responsive design.

Question Overview: This question tests the applicant's ability to work with data from a JSON file and translate it into a responsive design. This is a common task for front end developers, so you can use this question to see whether they're familiar with this process.

Sample Answer: I created a JSON file that contains information about a user's favorite movies. I then used JavaScript to read the file and display a list of movies on the page.

• - A working example of the code
• - A clear explanation of how the code works
• - A demonstration of the applicant's ability to work with JSON data

Resume Worded   |  Career Strategy

Front end developer interview questions.

The ultimate Front End Developer interview guide, curated by real hiring managers: question bank, recruiter insights, and sample answers.

Table of contents

Technical / job-specific, what are some best practices for writing maintainable and scalable css, what are the differences between inline, block, and inline-block elements in html/css.

• Explain the concept of specificity in CSS and how it impacts the rendering of HTML elements.

How do you optimize images for the web and improve page load times?

What are some html5 features that can enhance user experience on a website, explain the difference between var, let, and const in javascript., what are closures in javascript and why are they important, explain the concept of event delegation in javascript and why it is useful., what are promises in javascript and how do they help with asynchronous programming, can you explain how "this" works in javascript and how it is different from other programming languages, what are the differences between class components and functional components in react, explain the concept of state and props in react and how they are used in components., what is the purpose of keys in react and why are they important, what are hooks in react, and how do they change the way we write components, how do you handle forms and form validation in a react application, how would you diagnose and improve the performance of a slow-loading web page, what are some techniques to defer or asynchronously load javascript for better page performance, what are critical rendering path and its impact on web performance, how do you use browser developer tools to analyze web page performance, what are the main principles of web accessibility and why is it important for a front-end developer, how do you ensure keyboard accessibility for interactive elements on a web page, what is aria and how does it help improve web accessibility, how do you test a website for accessibility compliance and what tools do you use, behavioral questions, tell me about a time when you had to communicate a complex technical concept to a non-technical stakeholder. how did you ensure they understood the idea, describe a situation where you had to work with a team member who had a different working style than yours. how did you approach the situation and ensure seamless collaboration, can you describe a project where you implemented feedback from team members or stakeholders what was the feedback and how did you incorporate it, tell me about a time when you had to debug a complicated issue in the code. what was your process for identifying the problem and how did you solve it, have you ever faced a situation where there were multiple solutions to a problem how did you make the decision on the best approach, can you give an example of a coding challenge you faced and how you tackled it what steps did you take to arrive at a solution, describe a situation where you had to quickly learn a new technology or programming language. what resources did you use to learn and how did you ensure you were proficient in the new skill, have you ever faced a challenging project where you had to pivot or make changes to your initial plan how did you handle the situation and what was the result, tell me about a time when you had to adapt to a new working environment or team. what were the challenges and how did you navigate them.

• HTML and CSS
• Performance Optimization
• Accessibility
• Communication and Collaboration
• Problem-Solving and Decision Making
• Adaptability and Learning

Search Front End Developer Interview Questions

Want to test your knowledge? We've chosen ten Front End Developer interview questions in a random order that you can use as practice. As you go through the questions, say your answers out loud to practice your responses. Stuck on a question? Check out the insights or sample answers for hints. After you've attempted each question, read the sample answer to brush up your understanding. Let's dive in!

Interview Questions on HTML/CSS

Interview Questions on HTML and CSS

Interview Questions on JavaScript

Interview Questions on React

Interview Questions on Performance Optimization

Interview questions on accessibility, interview questions on communication and collaboration, interview questions on problem-solving and decision making, interview questions on adaptability and learning, interview guides similar to front end developer roles.

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• › Entry Level Front End Developer Interview Guide
• › JavaScript Developer (Front-End) Interview Guide
• › React Front End Developer Interview Guide

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Thank you for the checklist! I realized I was making so many mistakes on my resume that I've now fixed. I'm much more confident in my resume now.

Front End Developer Interview Questions (And Answers!)

This blog post will help you understand front end interviews and provide a sampling of common questions, as well as correct answers..

Table of Contents

Understanding the front end developer interview, javascript interview questions, css interview questions, html interview questions, algorithm questions, ecosystem questions.

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Interview Process

Front end interview processes can vary a lot by company. But, generally, they follow one of these two flows:

The Take-Home Interview

• Initial phone screen with a recruiter or hiring manager.
• A take-home challenge you complete on your own time.
• An onsite consisting of two or three in-person interviews. Likely covering or expanding on your take home.

The Standard Interview

• Phone screen with an engineer on the team.
• An onsite consisting of four or five in-person interviews.

The take-home challenges can range from building a complete front end application to a HackerRank style algorithm challenge. Sometimes a take home will be time-boxed to a set amount of time. One downside to take-home challenges is the additional time commitment. Also, if it's not time-boxed, you're essentially competing to be the person who spends the most time perfecting their answer. An upside is that most places that do take home interviews construct their follow-up interviews around the project you already completed.

This means, when preparing for front end developer interviews, you'll want to practice both the soft skills you'll need to do well on the recruiter or hiring manager screen, as well as the coding skills you'll need for the take-home and onsite.

What the Interviewer Is Looking For

When preparing for an interview, it's important to put yourself in the interviewer's shoes! If you've ever been on the other side of the table, draw on those experiences. They are likely in the middle of a workday with "Interview" on their calendar. Hopefully, they've looked at your resume and have been given some instructions from the hiring manager.

Some companies allow each interviewer to ask anything they want. Others maintain lists of "acceptable" or "banned" questions. Some even structure the entire interview process, assigning each person a specific subject to cover.

Either way, they have 45 minutes (typically) to meet you, introduce themselves, get to know you, and work through any coding challenges they may have brought. A good interviewer will outline the process in the beginning, but often they are broken down like this:

• The interviewer talks about themselves (2 minutes)
• The interview asks you to go through your recent work history (5 minutes)
• High-level technical questions (7 minutes)
• Coding challenge (25 minutes)
• The interviewee has a chance to ask questions (5 minutes)

Keep in mind some companies do things very differently. It's often a great idea to ask your recruiter for any information they can give regarding the interview process. Sometimes they will tell you the general structure, and other times they'll even give you a list of topics to study!

How To Approach Front End Developer Interview Questions

Interviews can be scary. The interviewee gets to pull a random question out of the air, and you have to get to work solving it! Keep in mind that there are many things you can do to improve your experience regardless of the question asked. Here are a few tips I always try to keep in mind:

• Don't start coding too quickly! Let them explain the question. Take a moment to make sure you really understand it. Ask clarifying questions. Maybe write a few "test cases," even if they are just pseudo code. For example, "So if I passed in the number 19837, it would return 13789"?
• Don't be afraid to ask questions. There may be some questions the interviewer won't answer, but asking questions will count in your favor most of the time!
• Break the problem down into smaller pieces. Coding challenges will often come wrapped in a big story. But at their core, they are usually relatively straightforward.
• Use magic functions! It's also quite common that you'll run into a discrete part you don't know how to solve while solving a coding challenge. Maybe you're writing code to access an API, and you've forgotten the syntax for `window.fetch`. Don't worry too much about it! Make a "magical" function like `getDataFromAPI` and just keep moving forward. It's always better to get something working than nothing at all. A well-named magic function can get you a long way. Things like `turnStringIntoArray`, `iterateThroughObject`, or `fetchChildDOMNode` can allow you to get back to the part of the problem you understand.

What is the `this` keyword in JavaScript?

`this` is a little tricky in JavaScript. Its value is determined by what the function you are inside of is called. In the global state, `this` is set to the window object. The value of `this` also depends on whether or not you are in strict mode . Inside a top-level function, a strict mode `this` will be undefined, whereas a non-strict mode `this` will be the window object. It's also worth knowing that the value of `this` can be overwritten with the bind method.

What is the difference between let, const, and var?

Originally, var was the only option JavaScript had for defining variables. In ES6, we got const and let as additional options. The important takeaways are:

• Variables defined with const cannot be reassigned.
• Const and let variables are block-scoped.
• Var variables are function scoped.
• Variables defined with var are hoisted .

What is the difference between == and ===?

Doubles equals checks for value only. Before checking, it does any necessary type coercion. For example, the string "1" will be == to the integer 1, but it will not be ===. Many projects these days prefer to always use ===. Although, some folks advocate writing code that works well with the == type coercion. 

How can you access HTML elements with JavaScript?

Familiarize yourself with getElementById , querySelector , and querySelectorAll . 

What options do we have to store data?

You can store user data in localStorage , cookies , or sessionStorage .

How can you traverse the DOM with JavaScript?

You can grab a DOM node with either `getElementById` or `querySelector`. You can then get all of its children by calling `.childNodes` (note: childNodes returns a NodeList , not an Array). You can then traverse the DOM by iterating through the childNodes and calling `.childNodes` on each one of them. You can walk your way back up by checking any node's `parentNode`.

For more information, check out all of the properties stored on DOM nodes .

What is functional programming in JavaScript?

Functional programming refers to using pure functions. In the context of JavaScript, this means familiarizing yourself with map , filter , and reduce . It's also worth understanding the concept of immutability.

What is the box model?

The CSS box model refers to the way CSS handles layout. Each element is composed of its content, padding, border, and margin.

Know your CSS selectors!

Many interview questions will require you to know class selectors like `.foo` and id selectors like `#bar`. It's also good to know that you can select siblings `div + p`, Descendents `div p`, and children `div > p`.

CSS specificity

If your CSS has two conflicting selectors, who wins? For example, if you write

Will the word "hello" be red or blue? To solve this, CSS has a priority order for which types of selectors win over other ones. `!important` tags are the strongest, and the universal `*` selector is the weakest. For a fun illustration to help you learn CSS specificity, check out specifishity.com .

What are pseudo-elements?

Pseudo-elements are keywords that let you specify specific parts of an element instead of the entire thing. For example, you can select an element's `::first-line` or select `::before` an element. 

What is Flexbox?

Flexbox is a W3 specified layout system for CSS. It allows you to easily position elements inside a container even if the size of that container is dynamic. You should familiarize yourself with some basic Flexbox layouts. Some free resources include:

• A Complete Guide to Flexbox
• Flexbox Zombies

What is CSS grid?

Grid is a W3 system for making entire page layouts. CSS Grid is great for literal grids and full pages, whereas Flexbox is great for groups of items on a page. Some free resources include:

• A Complete Guide to Grid
• CSS Grid Garden

What does semantic HTML mean?

Semantic HTML means using the most appropriate tag for the task at hand. It means using meaningful elements such as `<form>`, `<article>`, and `<table>` instead of only using `<div>` and `<span>`.

What is Web Accessibility?

Web Accessibility means making sure the web is usable by people with a wide range of disabilities. It includes making sure keyboard-only users can navigate your site while also making certain people who have difficulties hearing or seeing can use it as well.

What is the difference between a tag and an attribute?

HTML tags are elements. Think `<a>`, `<button>`, and `<div>`. HTML attributes describe characteristics of elements. Think `src`, `class`, and `id`.

What is the difference between inline and block elements?

Inline elements cannot have a height or width. Examples of inline elements include span, a, and img. Block elements get their own line and take up the full width available. Examples of block elements are div, p, and h1.

Display none vs. visibility hidden

Both display none and visibility hidden will hide the element from the page. The difference is that with display none, no space will be allocated for the element, whereas with visibility hidden, a blank space will appear on the page.

Front end interviews usually aren't as heavy on the data structures and algorithms as general software engineering interviews. Even so, it's still important to know how to accomplish a few everyday tasks.

You should know how to push, pop, shift and unshift. You should also know how to map, reduce, and filter.

You should know how to iterate through an object's keys . For extra credit, learn a bit about Sets and Maps and when to use them!

Lesser used data structures

Sometimes, other data structures will come up during an interview. You might get questions about Linked Lists, Stacks, Queues, and Trees. For a quick study guide on these, check out itsy bitsy data structures .

The most important thing to learn is some of the quirkier behavior of JavaScript's sort method. Make sure you can use it to accurately sort an array of integers. Sometimes front end interviews will also ask about specific sorting algorithms. To brush up on those, check out this article on freeCodeCamp.

Big-O notation

Time and space complexity comes up from time to time in front end interviews. At the very least, it's good to understand that any algorithm you write could be used on a very small or very large data set. This means things like adding a nested for loop could have profound effects at scale. If you want to go a little deeper, it's worth reading about Big-O notation and understanding some common notations like constant time and logarithmic time. This article on Digital Ocean is a great place to start.

What are some popular front end frameworks?

You definitely shouldn't need to know how to use multiple frameworks to get a front end job. But it might help to be aware of the current trends. Take a look at React , Vue , Angular , and Svelte . 

What are some alternatives to writing pure CSS?

Lots of teams use a CSS preprocessor like Less or SASS . Some teams use css-in-js libraries like styled-components . Others still use utility frameworks such as Tailwind . Again, no need to learn how to use all of these, but they are nice to be aware of at a high level!

What are some options for testing JavaScript code?

Unit test frameworks like Jest are very popular. Teams also use tools like Selenium or Puppeteer to test the entire website.

What is the difference between unit tests and end-to-end tests?

There is a ton of overlap but at a high-level unit tests mean testing your actual code. Making sure that functions return expected results when given specific inputs. End-to-end tests are intended to test the website itself, not the code. They simulate clicks and scrolls and make sure the site behaves accordingly.

What are TypeScript and Flow?

They are both types of systems for JavaScript. Similar to SASS and LESS mentioned above, they allow you to author JavaScript with static types, and then they turn into pure JS when you deploy. They can help you catch bugs and better document your code.

What is a bundler?

We like to author code by separating components into individual files. This makes it nice for us as developers but would be very slow if you try to force the user to load all 100+ files. Therefore we use a tool like webpack to grab all the files and concatenate them together. That way, we can serve 1 or 2 "bundles" of code instead of 100 individual files.

What is a CDN?

A Content Delivery Network like Cloudflare gives us geographically distributed servers so people can load our app from a location near them. Instead of people all over the world having to wait for files to come from your hometown.

What tools can you use to debug web applications?

All of the major browsers have a built-in set of developer tools . These can be used to look at network traffic, find errors in the console, spot memory leaks or CPU bottlenecks.

Back End Developer Interview Questions

What is an api.

API stands for Application Programming Interface. In front end development, we often use API to mean a REST service we can access with HTTP requests to get back data. For example, api.github.com/user will return information about the currently logged-in user.

How do you access an API with JavaScript?

The most common way to access an API with JavaScript is using `fetch`. 

What is the difference between SQL and NoSQL databases?

SQL databases (MySQL, PostgreSQL, etc.) are relational databases and come with a structured query language. NoSQL databases (MongoDB, DynamoDB) are non-relational and have dynamic schemas.

What is HTTPS?

Hypertext Transfer Protocol Secure is a version of HTTP (Hypertext Transfer Protocol) that is encrypted. This means that sensitive data like passwords are not able to be read while in transit. Any sensitive information should be sent over HTTPS. Companies like Google are even starting to push that all websites should be served over HTTPS as its become readily available and fast.

What is XSS?

Cross-Site Scripting attacks are when an attacker sneaks some malicious code into a web page viewed by others. Think of a social media site like Facebook. If you uploaded an image that looked like `<img src=" javascript:alert('hello everybody')"></img>`, you can imagine the surprise other users would have when they clicked on your image and saw a browser alert!

What is a SQL injection?

Another type of attack. If you have a search form, for example, and when a user types in a name like "Kelly" you take that string and do an SQL lookup for it. Let's say your SQL looks like this:

`SELECT * FROM Users WHERE UserId = yourVariable`

An attacker could put something malicious in the search bar like `Kelly OR 1=1`, and now it will return a list of all users instead of just the requested one.

Front End Developer Interview Tools

There are a ton of great resources to help you prepare for a front end interview. They all cover the same things, so if you have one you prefer, definitely use it! That being said, some of my favorite tools are:

• Leetcode - The de facto interview prep site with the largest number of sample questions.
• Cracking the Coding Interview - The de facto interview prep book.
• HackerRank - A Leetcode competitor but also the site most often used for take-homes. It's nice to get some hands-on experience with their UI before you begin.
• AlgoExpert - A new site with fewer sample questions than Leetcode but premium videos for each one.

Front end interviews can be stressful! There are infinite things to learn. I always recommend people study but be sure to study at a healthy pace. Set realistic goals and a time limit when you'll start applying for jobs.

If possible, always practice with real tools like a whiteboard or the hackerrank editor. Practice not only solving problems but learning to talk while you code. Remember, don't rush into coding! Ask questions until you fully understand the problem. Also, keep in mind you can fail a question and still get an offer! Just do your best, communicate what you can, and stay open to any feedback from the interviewer.

If you're looking to hire a front end developer , the G2i team is ready to introduce you to a network of over 1200 frontend speacialists from around the world. Get in touch today !

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30 Senior Front End Developer Interview Questions and Answers

Common Senior Front End Developer interview questions, how to answer them, and example answers from a certified career coach.

In the realm of web development, a Senior Front End Developer is considered a maestro orchestrating symphonies that captivate users with visually stunning and seamlessly interactive websites. As you gear up for your interview for such an influential role, it’s imperative to not only demonstrate deep technical knowledge but also showcase leadership qualities and problem-solving abilities.

This article will guide you through some typical Senior Front End Developer interview questions and provide tips on framing compelling answers. It aims to equip you with all the necessary tools to confidently articulate your skills, experience, and vision in your upcoming interview.

1. How have you ensured browser compatibility in your previous projects?

With the variety of browsers and devices in use today, cross-browser compatibility is a critical part of front-end development. Employers need to know that you’re capable of producing work that provides a consistent user experience, regardless of the platform. Hence, this question is asked to gauge your technical proficiency and problem-solving skills in dealing with compatibility issues.

Example: “In my experience, ensuring browser compatibility involves a few key steps.

One method is to use feature detection with Modernizr, which allows you to test if a particular feature is available in the user’s browser and provide fallbacks for unsupported features.

Another approach is to use cross-browser testing tools like BrowserStack or Sauce Labs. These tools allow you to test your application across different browsers and operating systems without needing to maintain multiple devices or virtual machines.

Lastly, adhering to web standards as much as possible can help ensure compatibility. This includes using valid HTML, CSS, and JavaScript, following accessibility guidelines, and avoiding proprietary technologies that may not be supported by all browsers.”

2. What’s the most challenging UI problem you’ve encountered and how did you resolve it?

This question is all about your problem-solving skills and adaptability. It’s one thing to be able to code and design according to a plan, but what happens when things don’t go as expected? The interviewer wants to see evidence of your ability to think on your feet and come up with creative solutions when faced with unexpected challenges. This speaks to your resilience, creativity, and overall competence as a developer.

Example: “One of the most challenging UI problems I faced was designing an application for both desktop and mobile platforms with a large amount of data. The challenge was to present all necessary information without overwhelming users.

I resolved this by implementing responsive design principles, ensuring the layout adapted to various screen sizes. To manage data presentation, I used progressive disclosure techniques. This meant only essential information was displayed initially, with additional details available upon user interaction.

This approach resulted in a clean, intuitive interface that enhanced user experience across devices.”

3. Describe a time when you had to optimize an application for better performance.

Every business wants its applications to run as smoothly and efficiently as possible. As a Senior Front End Developer, you are expected to have the skills to optimize applications for better performance. By asking this question, hiring managers want to gauge your understanding of performance optimization, your problem-solving skills, and your ability to handle complex tasks.

Example: “In one project, I noticed our web app was experiencing slow load times. After analyzing the issue, it became clear that large image files were causing the delay.

To optimize performance, I implemented a lazy loading strategy for images, so they only loaded when needed. This significantly reduced initial load time and improved user experience.

Furthermore, I used minification and bundling techniques on our JavaScript and CSS files to reduce their size and number of HTTP requests, which also contributed to faster load times.

These changes resulted in a 40% improvement in page speed, enhancing overall application performance and user satisfaction.”

4. In what ways have you utilized JavaScript frameworks in past work?

As a front end developer, you’re expected to be proficient in JavaScript and its related frameworks, as they are fundamental tools in web development. The ability to use these effectively can greatly enhance a website’s functionality and user experience. By asking about your experience with JavaScript frameworks, hiring managers aim to gauge your technical skills, creativity, and problem-solving abilities. They also want to understand how you’ve used these tools to drive project success in your previous roles.

Example: “In my previous projects, I have extensively used React.js for building user interfaces. Its component-based architecture helped in creating reusable UI elements and managing state effectively.

I’ve also worked with AngularJS to develop single-page applications. The two-way data binding feature reduced boilerplate code and improved readability.

Node.js was another framework I utilized for server-side scripting. It enabled efficient handling of asynchronous operations and boosted application performance.

Vue.js was used when simplicity and speed were crucial. Its easy learning curve and lightweight nature made it ideal for smaller scale projects.

Each JavaScript framework has its strengths, and choosing the right one depends on project requirements.”

5. Which coding standards do you adhere to ensure maintainability and readability of code?

Every developer has their own style, but when working on a team, it’s critical to have a common set of standards to ensure everyone’s on the same page. This isn’t just about making the code look nice, it’s about ensuring that the codebase remains maintainable and readable for everyone on the team, not just the person who wrote it. By asking this question, hiring managers are checking to see if you’re mindful of these issues and if you’ll be able to easily integrate into their existing development process.

Example: “I follow several coding standards to ensure maintainability and readability of code.

One such standard is adhering to a consistent naming convention, which helps in understanding the purpose of variables and functions at first glance. I also prioritize writing clear, concise comments that explain complex sections of code.

Another key practice is code modularity. Breaking down larger problems into smaller, reusable functions or components not only makes the code more readable but also easier to test and debug.

Lastly, I adhere to DRY (Don’t Repeat Yourself) principle. It reduces redundancy and potential for errors while increasing efficiency. Regular refactoring sessions are part of my routine to keep the codebase clean and manageable.”

6. Share an instance where you used data structures effectively while developing a front-end solution.

The essence of this question lies in understanding your proficiency with data structures and their application in real-world scenarios. It’s not just about knowing what data structures are, but how you can use them to optimize and streamline front-end solutions. This can showcase your problem-solving skills, your understanding of algorithmic efficiency, and your ability to create robust, efficient, and scalable code.

Example: “In one of my projects, I had to develop a feature that allowed users to filter and sort a large set of data. To achieve this efficiently, I utilized a combination of JavaScript arrays and objects.

The raw data was initially stored in an array. For filtering, I used the ‘filter’ method, which is quite efficient for such tasks. When it came to sorting, instead of directly sorting the array, I converted it into an object with keys as unique identifiers. This made lookups faster while maintaining the order of elements.

This approach significantly improved the performance of the front-end application, providing a seamless user experience even when dealing with substantial amounts of data.”

7. How would you approach converting a design mockup into a functional webpage?

This question is a staple for a front-end developer role because it directly addresses the main responsibility of the job. Understanding how you would approach converting a design mockup into a functional webpage helps the interviewer gauge your practical skills, problem-solving strategies, and attention to detail. It also provides insights into your proficiency with different tools and technologies, and your ability to collaborate with designers and back-end developers.

Example: “I would start by thoroughly reviewing the design mockup to understand all its elements. Then, I’d break it down into smaller components for easier management.

Next, I would determine the best technology stack based on project requirements and performance needs. This could include HTML/CSS for basic structure and styling, JavaScript or a framework like React for interactivity, and possibly CSS pre-processors for more complex styles.

After setting up the development environment, I’d begin coding each component, starting with the layout structure. During this process, I’ll ensure that the website is responsive and accessible.

Lastly, testing is crucial. I would conduct unit tests and cross-browser compatibility checks. After fixing any issues, the webpage will be ready for deployment.”

8. Have you ever implemented responsive design? If so, describe the process.

Responsive design is a fundamental aspect of modern web development, given the multitude of devices and screen sizes that users can access a website from. The question is aimed at gauging your expertise and experience in this area, as well as your ability to problem-solve and adapt to different scenarios. It also gives interviewers a chance to understand your process and how you approach design challenges.

Example: “Yes, I have implemented responsive design numerous times. The process begins with understanding the user’s needs and designing a layout that adapts to various screen sizes.

I usually start by creating a flexible grid system using CSS. This allows for easy adjustment of elements based on viewport size.

Then, I use media queries to adjust the CSS properties as per different device breakpoints. This ensures the website looks good on all devices, from mobiles to large desktop screens.

Finally, I test the design on multiple devices and browsers to ensure consistency in appearance and functionality. Any issues discovered during testing are fixed before final deployment.”

9. What is your strategy for testing and debugging front-end applications?

The inner workings of an application are just as important as its outward appearance. A front-end developer must ensure the app functions correctly and is user-friendly. This question is designed to assess your problem-solving skills and diligence in identifying and resolving issues. It also helps employers understand your proficiency in using various tools and techniques for testing and debugging.

Example: “My testing and debugging strategy for front-end applications involves a mix of manual and automated methods. I use unit tests to verify individual components in isolation, ensuring they function as expected. Integration tests are used to check if different parts work well together.

For debugging, I rely on browser developer tools like Chrome DevTools. It allows me to inspect elements, monitor network requests, and debug JavaScript code directly in the browser.

I also believe in the importance of user testing. Observing real users interacting with the application often reveals issues that were not caught during development. This feedback is invaluable for improving usability and overall user experience.”

10. Detail your experience with CSS preprocessors like SASS or LESS.

Diving into your experience with CSS preprocessors allows hiring managers to assess your technical skills and understand how you approach efficiency in coding. Preprocessors can streamline and enhance CSS, making your work more scalable and maintainable. Your familiarity with them reflects your capacity to handle complex projects and improve workflows, vital for a senior role.

Example: “I have extensive experience with CSS preprocessors, particularly SASS. I’ve found it to be a powerful tool in writing DRY (Don’t Repeat Yourself) and maintainable stylesheets. It’s helped me manage large-scale projects by organizing code into reusable modules.

The use of variables for colors, font sizes or other repetitive values has been invaluable. Mixins and functions have allowed me to create reusable styles that can be customized with arguments.

Nested syntax is another feature I frequently use, as it helps keep the code clean and easy to read. Overall, using SASS has significantly improved my efficiency and productivity as a front-end developer.”

11. How have you handled user accessibility in your web development projects?

Web accessibility is a critical aspect of front-end development. This question helps the interviewer understand your awareness and commitment to creating inclusive digital environments. Ensuring that your web projects are accessible to all users, including those with disabilities, not only demonstrates your technical skills but also your empathy and understanding of diverse user needs.

Example: “In my web development projects, accessibility is a priority. I use semantic HTML to provide meaningful structure and ensure that screen readers can accurately interpret the content.

I also implement ARIA roles and properties where necessary to enhance accessibility. This helps in providing additional context to assistive technologies.

Color contrast and font sizes are another key consideration for visually impaired users. I adhere strictly to WCAG guidelines to ensure optimal readability and visibility.

Finally, keyboard navigation is crucial for those who cannot use a mouse. I always ensure all functionality can be accessed using only a keyboard.”

12. What are some SEO principles you’ve applied in your front-end development practices?

As a senior front end developer, you’re not just there to make a website look good and function well. You’re also there to ensure that the site is optimized for search engines—i.e., that it’s discoverable. This question is meant to test your understanding of how front-end development and SEO intersect, and to see if you have the skills necessary to create a website that’s both user-friendly and easily found by search engines.

Example: “In my front-end development practices, I’ve applied various SEO principles to enhance website visibility and ranking.

I ensure that the site is mobile-friendly as Google prioritizes mobile-first indexing.

I use semantic HTML tags for better understanding of page structure by search engines.

I optimize load times by minimizing HTTP requests, enabling compression, and optimizing images, as speed is a crucial factor in SEO.

I also implement structured data markup for rich snippets which can significantly improve click-through rates.

Moreover, I take care of meta tags such as title and description for each page, ensuring they are unique and descriptive.

Lastly, I make sure that the website is easily crawlable by structuring URLs logically and using breadcrumbs for improved user navigation.”

13. Provide an example of a project where you used Angular, React, or Vue.js extensively.

A front-end developer’s proficiency in popular JavaScript frameworks such as Angular, React, or Vue.js is a key aspect of their skill set. By asking this question, recruiters are trying to understand your familiarity and expertise with these tools. They want to assess how well you’ve used these technologies in the past, how you’ve applied them to solve problems, and how effectively you can leverage them to meet the company’s needs.

Example: “One notable project where I used React extensively was developing an interactive dashboard for a financial services client. The dashboard provided real-time data visualization of market trends and user portfolio performance.

I leveraged React’s component-based architecture to build reusable UI elements, ensuring consistency across the platform. For state management, I utilized Redux which enhanced the predictability of the application’s behavior.

To handle asynchronous actions, I incorporated Redux Thunk middleware. This allowed us to dispatch functions in addition to objects, making it easier to manage API calls.

The use of React resulted in a highly responsive, scalable, and maintainable application that significantly improved our client’s user experience.”

14. How do you stay updated on the latest front-end technologies and trends?

The tech industry is constantly evolving, and as a front-end developer, you’re expected to keep up with the pace. Employers want assurance that you’re passionate about your field and proactive in staying current. They need to know that you can adapt to new technologies and apply them effectively to keep the company competitive and innovative.

Example: “I stay updated on the latest front-end technologies and trends through a variety of methods. I follow industry leaders and influencers on social media platforms like Twitter, where they often share updates and insights.

Subscribing to newsletters from reputable tech websites and blogs also helps me keep abreast of new developments. Websites such as Smashing Magazine, CSS-Tricks, and Frontend Focus provide valuable information.

Participation in online communities like Stack Overflow or GitHub is another way I engage with other developers, learn about emerging tools, and discuss best practices.

Lastly, attending webinars, workshops, and conferences provides deeper understanding and hands-on experience with new technologies. This multi-faceted approach ensures that I’m always at the forefront of any significant changes in the field.”

15. How have you managed version control systems like Git in your workflow?

Version control is a critical part of any software development process, ensuring that teams can work collaboratively without overwriting each other’s changes and that any issues can be rolled back if necessary. Therefore, hiring managers want to know that you’re not just familiar with version control systems like Git, but that you can use them effectively as part of a team. Additionally, your answer can give insight into your workflow habits, your understanding of collaborative environments, and your ability to handle and prevent potential conflicts in the codebase.

Example: “In my workflow, I use Git for version control to track and manage changes to the codebase. For each new feature or bug fix, I create a separate branch off the main development branch. This allows me to work on multiple tasks simultaneously without affecting the stability of the main code.

I commit changes frequently with clear, descriptive messages to ensure that every step in the development process is documented. This makes it easier to identify when and where bugs were introduced.

Before merging any branches, I perform a rebase to keep the project history clean and understandable. Finally, I always make sure to review and test all changes before they are merged into the main branch. This helps maintain the quality and integrity of our codebase.”

16. Tell us about a situation where you improved website load times significantly.

The essence of this question lies in the fact that user experience is significantly impacted by website performance, and load time is a key factor. As a senior front-end developer, your potential employer wants to know that you can optimize code, leverage best practices, and use advanced tools to create a seamless and fast-loading user experience. This question gives you the opportunity to showcase your technical skills, problem-solving abilities, and the positive impact of your work.

Example: “In a recent project, the website was suffering from slow load times. I identified large image files as the main culprit. To address this, I optimized all images using tools like TinyPNG and implemented lazy loading to only load images when they’re in view.

I also minified CSS, JavaScript, and HTML files which reduced their size and consequently improved load time.

Further, I used Google PageSpeed Insights for performance analysis and found render-blocking resources were causing delays. By deferring non-critical JS/CSS, we managed to speed up content rendering.

The result was a significant improvement – load times dropped by 40%. This not only enhanced user experience but also positively impacted SEO rankings.”

17. Walk us through your process of handling form validation on a complex input page.

The essence of this question is to assess your understanding of user experience and form handling. As a developer, you’re expected not only to write functional and efficient code but also to create a seamless user experience. This includes handling and validating form input to ensure it meets the required format and criteria. This question helps the interviewer understand your attention to detail, problem-solving skills, and your ability to create user-friendly applications.

Example: “For form validation, I typically use a combination of client-side and server-side validation. Client-side for immediate feedback to the user, and server-side as a security measure.

I’d start by setting up basic HTML5 validations such as ‘required’, ‘pattern’ etc., then enhance this with JavaScript or a library like jQuery Validation Plugin for more complex rules.

On the server side, I would re-validate all data received from the client, using a server-side language like PHP or Node.js. This ensures that even if someone bypasses our client-side checks, invalid data won’t be processed.

Handling errors is also critical. For any validation error, I ensure clear messages are displayed near the relevant input field so users know what needs correcting. If it’s an asynchronous operation, I use AJAX to post the form and display any errors without a page refresh.”

18. Describe a scenario where you had to refactor existing code to improve its efficiency.

The ability to critically evaluate and improve existing code is a key skill for a senior front-end developer. This question helps interviewers assess your problem-solving skills, your understanding of coding efficiency, and your ability to work with legacy systems. It can also give them insight into your thought process and how you approach challenges in your work.

Example: “In one project, we had a data-intensive application that was slow due to redundant API calls. The code was written in such a way that every component made its own API call, leading to unnecessary network requests.

I refactored the code by implementing a shared state management system using Redux. This allowed us to make a single API call and share the response among all components.

This change significantly improved the performance of our application, reduced the load on our server, and provided a smoother user experience. It also made the codebase easier to maintain as there was now a single source of truth for our data.”

19. How familiar are you with web security measures to prevent cross-site scripting or SQL injection attacks?

In today’s digital age, cyber threats are ubiquitous and can cause serious damage to an organization’s reputation and bottom-line. Understanding your familiarity with web security measures is a way for the employer to gauge your ability to design and implement secure and robust front-end solutions. Your knowledge in preventing common web attacks such as cross-site scripting or SQL injection attacks is vital in ensuring the safety of the company’s data and its users.

Example: “I’m well-versed in web security measures to prevent cross-site scripting and SQL injection attacks. I ensure the use of prepared statements with parameterized queries for SQL, which prevents attackers from injecting malicious code.

For XSS attacks, I implement output encoding when displaying user input back on the page. This converts potentially harmful characters into their HTML-encoded equivalents.

Incorporating Content Security Policy headers is another strategy I employ. It instructs browsers to limit how and what third-party assets can be loaded, reducing potential attack vectors.

Regularly updating and patching systems also forms part of my approach to maintaining robust security.”

20. Give an example of a project that required extensive use of AJAX or Fetch API.

This question is a dive into your practical experience with key technologies in front-end development. AJAX and Fetch API are important tools for creating seamless user experiences on the web, as they allow for asynchronous data exchange between a user’s browser and a server. By asking for specific examples, hiring managers are looking for proof that you’ve used these technologies effectively in the past, and that you understand their benefits and drawbacks.

Example: “One project where I extensively used AJAX was a real-time chat application. The app required constant communication with the server to fetch new messages without refreshing the page.

I used AJAX for sending user input to the server and retrieving updated chat data. This ensured seamless interaction between users, providing an experience similar to popular messaging apps.

The Fetch API was also used to handle errors more effectively and provide better browser compatibility.”

21. How comfortable are you working with back-end developers and integrating their APIs into your front-end code?

Front-end developers are often expected to collaborate closely with their back-end counterparts to ensure the website or application functions seamlessly. This often involves integrating APIs developed by back-end engineers into front-end code. So, interviewers want to gauge your comfort level and experience in this collaborative, cross-disciplinary aspect of the role, which essentially determines the end-user experience.

Example: “I am very comfortable working with back-end developers and integrating their APIs into my front-end code. In fact, I believe that seamless collaboration between front-end and back-end teams is crucial for successful project delivery.

Over the years, I’ve developed a good understanding of RESTful principles, which helps me integrate APIs effectively. I also have experience in handling data formats like JSON and XML.

Moreover, I always ensure to communicate clearly with the back-end team about endpoints, methods, and expected data structures. This aids in avoiding any potential misunderstandings or issues down the line.

In essence, I see this integration as an integral part of my role as a Front-End Developer and approach it with due diligence and expertise.”

22. When faced with a tight deadline, how do you prioritize your tasks?

As a senior front-end developer, you’ll likely be juggling multiple tasks at any given time. Employers want to know you can effectively manage your workload and deliver quality results, even when under pressure. Understanding how you prioritize tasks gives them insight into your decision-making process, your ability to meet deadlines, and how well you manage stress.

Example: “When faced with a tight deadline, I prioritize my tasks based on their impact and urgency. Impact refers to how much the task will contribute to the final product, while urgency is about the time sensitivity of the task.

I use a method similar to the Eisenhower Box for this. High impact, high urgency tasks are done first. Lower urgency tasks, even if they have high impact, can be scheduled for later. Low impact tasks are delegated or eliminated.

This approach ensures that the most critical aspects of the project are addressed first, thus reducing risk and ensuring timely delivery. It also helps in maintaining code quality as it prevents rushing through important tasks.”

23. What methods have you used to make your websites mobile-friendly?

In today’s digital age, mobile optimization is non-negotiable. With the majority of users accessing the web primarily through mobile devices, your ability to create a seamless, efficient, and visually appealing mobile experience is essential. Interviewers need to know that you have the skills and experience to design websites that look and function optimally on all devices, not just desktop computers.

Example: “In order to make websites mobile-friendly, I’ve used responsive design principles and CSS media queries. This allows the layout to adapt based on the screen size.

I also focus on touch controls, ensuring buttons and links are large enough for easy interaction. Load times are crucial too, so optimizing images and minifying code is part of my process.

Furthermore, I use tools like Google’s Mobile-Friendly Test to identify any potential issues that might affect usability or SEO rankings.”

24. How proficient are you in using developer tools for debugging and performance tuning?

This question is all about your technical skills and how you approach problem-solving. As a senior front-end developer, you’ll often be tasked with identifying and fixing issues that impact a website or app’s performance. This can involve anything from debugging JavaScript to optimizing load times. By asking about your use of developer tools, interviewers are trying to gauge your ability to troubleshoot and enhance the user experience effectively.

Example: “I am highly proficient in using developer tools for debugging and performance tuning. I regularly use Chrome Developer Tools, which allows me to interact with web pages in real time, debug JavaScript, analyze network activity, and optimize load performance.

For more complex issues, I turn to tools like Webpack Bundle Analyzer and Lighthouse to gain deeper insights into the application’s behavior and resource usage.

In terms of coding, I follow best practices such as modular programming and code reviews to minimize bugs from the onset. This proactive approach reduces the need for extensive debugging later on.

Overall, my proficiency in these tools and methodologies ensures that I can efficiently troubleshoot issues and enhance performance.”

25. Share an experience where you had to work with a difficult team member on a project.

As a Senior Front End Developer, you’re not only expected to be a technical wizard, but also a team player. This means being able to navigate the complexities of group dynamics and handle difficult colleagues when needed. By asking this question, hiring managers are trying to gauge your interpersonal skills, conflict resolution abilities, and leadership potential. Your answer could reveal your capacity for empathy, patience, and maintaining a positive work environment, all of which are vital in a collaborative field like software development.

Example: “In a recent project, I had to work with a team member who was not meeting deadlines. This was impacting the overall progress of our front-end development tasks.

Instead of confronting him directly, I initiated an open discussion during our stand-up meetings about the importance of adhering to timelines for successful project completion.

I also offered my assistance and shared some strategies that helped me manage my time effectively. Over time, his performance improved significantly which positively impacted our project delivery. It was a learning experience on handling team dynamics and enhancing productivity.”

26. Describe how you’ve used user feedback to improve a web application’s UI/UX.

User feedback is the cornerstone of improving any user interface (UI) or user experience (UX). As a potential hire, you need to demonstrate that you can translate user feedback into actionable improvements. It shows that you can listen to and collaborate with users, and that you value their input in the design process. This skill is essential for creating products that are not only functional, but also user-friendly and engaging.

Example: “In one of my projects, we received feedback that users were having difficulty navigating the site. We used this feedback to conduct usability testing and identified several areas for improvement.

We redesigned the navigation menu making it more intuitive and user-friendly. The search functionality was improved by adding filters and predictive text features.

Post-implementation, we conducted another round of user testing and surveys. The changes led to a significant increase in user satisfaction and engagement levels. This experience underscored the importance of user feedback in enhancing UI/UX.”

27. What is your approach towards handling browser inconsistencies in your code?

Cross-browser compatibility is a significant challenge in front-end development. With a plethora of browsers, versions, and devices in use, code often behaves differently from one environment to another. Hence, interviewers want to know if you understand these discrepancies and have strategies in place to address them. They want to see if you can ensure that the end product provides an optimal user experience across all platforms.

Example: “To handle browser inconsistencies, I first ensure to write clean, valid and standards-compliant code. This reduces the chances of encountering such issues.

Next, I use feature detection techniques like Modernizr to determine if a certain feature is supported in the user’s browser or not. If it isn’t, I provide an alternative solution or fallback.

I also make use of CSS resets or normalizers to create a consistent baseline across browsers.

Lastly, extensive cross-browser testing is crucial. Tools like BrowserStack can be very helpful for this purpose.

In essence, my approach combines preventative measures with responsive solutions to manage browser inconsistencies effectively.”

28. Tell us about a time when you innovated a solution to enhance website interactivity.

The crux of a senior front-end developer’s role lies in innovation and problem-solving. This question is asked to assess your creativity, technical prowess, and your ability to improve user experience. It also gives an insight into your understanding of the latest trends in web development and how you apply these trends to create engaging, intuitive, and user-friendly interfaces.

Example: “At a previous company, we were facing high bounce rates on our product pages. I hypothesized that users weren’t engaging because they couldn’t visualize the product well.

To solve this, I proposed an interactive 360-degree view feature. This would allow users to rotate and zoom in on products for a more immersive experience.

I led the development of this feature using Three.js library for 3D rendering. Post-implementation, we saw a significant decrease in bounce rate and an increase in time spent on product pages. It was a clear indication that enhancing interactivity can greatly improve user engagement.”

29. How well do you handle working with legacy code? Give an example.

Dealing with legacy code is a common challenge for developers. It can be complex, poorly documented, and difficult to understand. However, it’s often a key part of a company’s existing systems. Asking this question, hiring managers want to understand your ability to navigate, understand, and improve upon existing code rather than simply wanting to start from scratch. They’re looking for problem-solving skills, patience, and an understanding of the importance of maintaining and improving what’s already in place.

Example: “Working with legacy code can be challenging, but I’ve found it to be a valuable opportunity for learning and problem-solving. For instance, in one project, we had an older JavaScript framework that was causing performance issues.

I started by understanding the existing system thoroughly before making any changes. This involved reading through the documentation, studying the coding patterns used, and running tests to identify bottlenecks.

Next, I refactored critical parts of the application using modern frameworks like React while ensuring backward compatibility. Regular testing ensured no functionality was lost during this transition.

This approach not only improved the app’s performance but also made it easier for the team to maintain and update the system moving forward.”

30. Detail an instance where you successfully met a tight deadline without compromising the quality of your codes.

This question is critical because it gauges your ability to handle pressure while maintaining high performance. In a rapidly evolving tech industry, time is of the essence. However, the quality of work should not be compromised. Therefore, your potential employer wants to know how you balance timely delivery with creating error-free, efficient codes.

Example: “In one instance, I was tasked with implementing a new feature on our company’s website within two days. The challenge was to ensure the code quality and functionality weren’t compromised due to the tight deadline.

I started by breaking down the task into smaller manageable parts and prioritizing them based on their complexity and importance. This helped me focus on each part without feeling overwhelmed by the whole project.

Next, I used automated testing tools throughout the development process to catch any bugs or issues early on. This saved time as it reduced the need for extensive debugging later.

Despite the pressure, I managed to complete the task within the given timeframe. The new feature worked seamlessly and there were no significant issues post-deployment, demonstrating that even under tight deadlines, quality does not have to be sacrificed.”

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Lesson 9 of 34 By Ravikiran A S

Table of Contents

⏱️ 9min read                                                                             Difficulty level: Easy 380K+ career-aspirant learners have read this article 👨🏻‍💻 on frontend developer interview Q&As!

Frontend Developers are in demand today. A lot of companies are readily hiring them with attractive salary packages. If you believe you possess the skills to become a frontend developer and wish to make a career in it, then you’re in the right place. This tutorial on Frontend Developer Interview Questions will help you crack your next interview. This Frontend Developer Interview Questions tutorial has put together questions on various languages and frameworks used for frontend development.

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Front End Developer Interview Questions for Freshers

1. what are meta tags in html .

• Meta tags are those tags which go inside the Head tag of the HTML page
• Meta tags are not for the interface they are important for the browser. 
• Meta Tags are always in name or value pairs 
• Meta tags consist of character encoding, title, or even description. 

2. State some basic design element

Some of the basic elements of design are 

• Line - a line mark made with any pen or brush or even any edge created when two shape meets 
• Size - it is the area occupied by one shape with the other 
• Texture- the surface of the shape - Smooth, soft, hard, glossy, and such 
• Color - The light reflected from the objects. The three characteristics of color are hue, value, and the intensity. 

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3. What is load balancing? 

Load balancing is distribution of all the incoming network traffic all across the backend servers. 

4. What npm stands for ?

Npm stands for Node Package Manager. 

5. What is scope in JavaScript? 

In JavaScript every function has its own scope. It is basically a collection of rules for how variables are accessed and variables itself. 

6. How are JavaScript and jQuery different?

JQuery is a library built with the JavaScript language, and JavaScript is the language itself. 

7. What is Content Security Policy? 

Content security Policy also known as CSP, is a header in HTML which lets the soite operators  gain the whole control over the resources which are loading on the site. 

8. What is Cross-Site Scripting (XSS)?

XSS, Cross-Site Scripting is an attack which takes place when any attacker uses a web application to send any malicious code, in the form of browser side script, to another user. 

9. What is User Centered Design?

User-centered designs are those designs the designer solely focuses on which are according to the needs of users and them in every phase of designing. 

10. What is callback hell?

JavaScript which uses callbacks and is hard to get the right intuitively. The callbacks which are stacked in the form of pyramid structure. 

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11. What is Polymorphism ?

The word Polymorphism means having many different forms. If we talk in object-oriented form, polymorphism refers to one interface, multiple functions. 

12. What is Strict Mode?

A new feature of ECMAScript 5 is Strict mode which lets you place a function, or a program in a “strict” context of operating. 

13. What is meant by the KISS principle? 

KISS, a backronym of “Keep it simple, stupid”. Which was the principal design in the US Navy in 1960. The KISS principle states that the simpler the system the better it works. 

14. What does SOLID stand for?

S.O.L.I.D is an acronym of object-oriented design principles 

S- single responsibility principle 

O- open-closed principle 

L- Liskov Substitution principle 

I- interface segregation principle 

D- dependency. 

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15. What is ClickJacking?

ClickJacking is an attack which lets the developer fool the users into thinking that they are clicking one thing but actually they are clicking the other one. 

16. What is Coercion in JavaScript? 

The conversion of two different build-in Types of JavaScript is called Coercion. It comes in two forms, Explicit and implicit. 

17. What is IIFEs?

IIFEs stands for Immediately-Invoked Function Expression. This executes immediately after you create it. 

18. What is a grid system in CSS?

A structure which lets the content be placed both horizontally and vertically in a consistent and manageable way. There are two key components of the Grid system; Rows and Columns. 

Beginner’s guide to start your career with Front End Development skills

19. What is Mixin?

A Mixin is a code block that lets the group of CSS declarations which we can reuse in our site. 

20. Mention ways to decrease page load time?

The best ways to decrease the page load time is 

• Image optimization
• Browser cache
• Compress and optimize content 

Front End Developer Interview Questions for Experienced 

1. what is stringify.

To transform a JavaScript object to a string Stringify is used. 

2. State the elements of the CSS Box Model.

CSS Box Model consist of 4 elements 

3. What is the benefit of Srcset?

When we want to generate many new solutions of exact images on several devices, Srcset is used. This helps improve the UI. 

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4. What is MySQL?

MySQL is a relational Database Management System which uses SQL as its standard language to manage its database. MySQL just like other databases uses a Table-like structure. 

5. What is MongoDB?

MongoDb is a NoSQL database which shows the data elements using JSON-like Structure. To make changes in MongoDB the programmer has to use MongoBD Query Language.

Git Interview Questions

1. what is ‘version control system’ .

A version control system (VCS) is a program that records any changes to a file or set of data so that it is possible to restore it to a previous version if necessary. This guarantees that everyone on the team is working on the most up-to-date version of the file. 

2. Differentiate Between Centralized and Distributed Version Control System

In a Centralized Version Control System: 

• It stores all file versions on a central server.
• No developer has a complete copy of the local system's files.
• If the project's central server fails, you will lose all the project's data.

In a Distributed Version Control System:

• Every developer has a copy of all the code versions on their computer.
• Improves the ability to work offline and eliminates the need for a single backup location.
• Even if the server crashes, there is no danger.

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3. Explain Git Push and Git Pull

Git push is a command that pushes the contents of a local repository to a remote repository. It runs a push after it has changed a local repository to share the changes with remote team members.

Git pull is a command that pulls changes from a remote repository and merges them into the local repository. It's made up of two commands: git fetch followed by git merge.

4. Name a few Git Commands and function

• Git Config - Configure the username and email address
• Git init - Initialize a local Git repository
• Git Add - Add one or more files to the staging area
• Git Diff - View the changes made to the file
• Git Commit - Commit changes to the head but not to the remote repository
• Git reset - Undo local changes to the state of a Git repo
• Git Status - Displays the state of the working directory and staging area
• Git Merge - Merge a branch into an active branch
• Git Push - Upload content from the local repository to a remote repository
• Git Pull - Fetch and download content from a remote repository

Also Read: How to Become a Front End Developer?

5. Explain the Difference Between Git Pull and Git Fetch

• It downloads only new data from a remote repository using Git fetch
• It does not include any of this new information in your working files
• To update the remote-tracking branches, run Git fetch at any time
• Command - git fetch origin

              git fetch –-all

• Git pulls new data and integrates it with the current working files, updating the current HEAD branch with the latest modifications from the remote server
• It attempts to combine remote modifications with those made locally
• Command - git pull origin master

6. What is a Merge Conflict in Git and how can it be resolved?

When you have merging branches with opposing commits, a merge conflict occurs, and Git needs your help to select which changes to include in the final merge.

Resolve using GitHub conflict editor

When competing for line changes, i.e. when users make different modifications to the same line of the same file on different branches in your Git repository, this is done to avoid merging conflicts.

Step 1: Under your repository name, click Pull requests. 

Step 2: Click the pull request with the merge conflict you'd like to resolve in the "Pull Requests" list. Click Resolve conflicts near the bottom of your pull request.

Step 3: Decide whether you want to maintain just your branch's changes, only the other branch's changes, or make a completely new modification that includes both branches' changes. 

Step 4: Delete the conflict markers and make the changes you want in the final merge. 

Step 5: If your file has over one merge conflict, scroll down to the next set of conflict markers and repeat steps four and five to resolve the issue. Mark the file as resolved once you've resolved all the conflicts.

Step 6: If you have more than one file with a conflict, go to the left side of the screen and select the next file you wish to edit under "conflicting files". Then repeat the above steps until you've resolved all the merge conflicts in your pull request.

Step 7: Click Commit merge once you've resolved all of your merge conflicts. It merges the entire base branch into your head branch as a result of this. Click Merge pull request to combine your pull requests.

Resolve the issue with a local clone of the repository and commit the update to your GitHub branch.

It resolves all other forms of merge conflicts using this method. To push the update, you can use the command line or a program like GitHub desktop.

Step1: Open Git Bash. Go to the local Git repository where the merge conflict exists.

Step2: Make a list of the files that have been affected by the merge dispute. In this case, there is a merge conflict in the file styleguide.md.

Step 3: Navigate to the file with merge conflicts in any text editor, such as Sublime Text or Atom. Look for the conflict marker "<<<<<<" if you want to see where the merging conflict started in your file.

After the line "<<<<<<HEAD", you'll see the changes from the base branch.

Step 4: Next you’ll see =======, which divides your changes from the changes in the other branch, followed by >>>>>>> BRANCH-NAME

Step 5: Decide whether you want to simplt maintain your branch's changes, only the other branch's changes, or make a completely new modification that includes both branches' changes.

Step 6: Delete the conflict markers, <<<<<, =====, >>>>> and make changes you want in the final merge. 

Step 7: Add or stage your changes. Commit your changes with a comment. 

You may now combine the branches using the command line, or you can upload your changes to your GitHub remote repository and merge them in a pull request.

Also Read: Git Rebase vs. Merge

7. What is Git Stash?

8. Differentiate Between Git Merge and Git Rebase

Assume you're working on a new feature in a dedicated branch, and another team member pushes new commits to the master branch. 

Merge is used to incorporate new commits into your feature branch. Every time you need to include modifications, this requires an extra merging commit. It taints the history of your feature branch.

You can rebase the feature branch into master instead of merging it. This incorporates all the new commits in the master branch. It also re-writes the project history by creating brand new commits for each commit in the original branch.

This brings us to the end of Git Questions. These are some of the most important Front End Interview Questions related to Version Control.

HTML Interview Questions

HTML is an integral part of Frontend Development. The following set of Frontend Developer Interview Questions are based on HTML. 

1. What Is an Attribute in HTML?

<h1>Hello</h1>

<p>Welcome</p>

<h2>Click on the button to subscribe</h2>

<button>Subscribe</button>

• Attributes are the properties that can be added to an HTML tag that change the way the tag behaves or is displayed.
• It adds attributes right after the name of the HTML tag, inside the brackets. 

2. What is Marquee in HTML?

• The marquee is used to scroll the text on the webpage.
• It automatically scrolls the image or text up, down, left, or right.
• You must use <marquee> tags to apply for a marquee.

3. What is Semantic HTML? How does it work?

• Semantic HTML is a type of coding.
• It is the use of HTML markup to emphasize the content's semantics or meaning.
• Consider the following scenario: The <b></b> tag is not used for bold statements in semantic HTML, while the <i></i> element is used for italic.
• Instead, you use the <em></em> and <strong></strong> tags.

Also Read: An Ultimate Guide on How to Start Coding 2022

4. How do you Display a Table on an HTML Webpage?

• To display data in a tabular format, use the HTML table> tag.
• It's also utilized to control the page's layout, such as the header section, navigation bar, body content, and footer section.

5. What is SVG in HTML?

<svg width="100" height="100">

      <circle cx="50" cy="50" r="40" stroke="yellow" stroke-width="4" fill="red" />

    </svg>

• HTML SVG is a markup language that describes vector and raster graphics. XML text files define SVG pictures and associated behaviors.
• It's typically used for X, Y coordinate system diagrams like pie charts and 2-Dimensional graphs.

6. In HTML, how do you separate a section of text?

In HTML, you use the following tags to divide a chunk of text:

<br> tag–It's a character that's used to break up a line of text. It transfers the text flow to a new line by breaking the existing line.

<p> tag–This tag is used to create a text paragraph.

<blockquote> This tag is used to indicate big quoted passages.

7. How do you Create Nested Web Pages in HTML?

<!DOCTYPE html>

    <html>

      <body>

        <h2>HTML Iframes example</h2>

        <p>

          specify the size of the iframe using the height and width attributes:

        </p>

        <iframe src="https://simplilearn.com/" height="600" width="800"></iframe>

      </body>

    </html>

• You refer a webpage within a webpage to as a nested web page.
• Using HTML's built-in iframe tag, you can create nested web pages.

8. Differentiate Between Ordered List and Unordered List

        <h2>HTML List Example</h2>

        <ul>

          <li>Coffee</li>

          <li>Tea</li>

          <li>Milk</li>

        </ul>

        <ol>

        </ol>

• An unordered list uses <ul> </ul> tags and each element of the list is written between <li> </li> tags.
• An ordered list uses <ol> </ol> tags and each element of the list is written between <li> </li> tags.

Now that we are familiar with HTML questions, let’s look at the next set of Frontend Developer Interview Questions, CSS 

CSS Interview Questions

1. what is the best way to include css styling in html.

There are three methods for incorporating CSS into HTML :

• You use inline CSS when only a single element needs to be styled or when a little quantity of styling is required.
• External Style Sheet: When a style is applied to many elements or HTML pages, it employs an external style sheet.
• Internal Style Sheet: An internal style sheet is employed when a single HTML document has a distinct style and numerous elements.

Also Read: 11 Secrets about CSS That You Mustn’t Miss

2. Mention the different types of CSS Selectors

//Universal Selector

        color: "green";

        font-size: 20px;

        line-height: 25px;

//Element type Selector 

    line-style: none;

    border: solid 1px #ccc;

// ID Selector 

#container {

    width: 960px;

    margin: 0 auto;

  <div id="container"></div>

//Class Selector 

    padding: 10px;

    margin: 10px;

    width: 240px;

  <div class="box"></div>

//Descendent Combinator

 #container .box {

    float: left;

    padding-bottom: 15px;

<div id="container">

    <div class="box"></div>    

    <div class="box-2"></div>

</div> 

<div class=”box”></div>

//Child Combinator

 #container> .box {

    <div class="box"></div>   

    <div>

        <div class="box"></div>

    </div>

// General Sibling Combinator

    margin-bottom: 20px;

<h2>Title</h2>

<p>Paragraph example.</p>

<div class=”box”>

    <p>Paragraph example.</p>

</div>

//Attribute Selector 

input [type=”text”] {

    background-color: #444;

    width: 200px;

<input type="text">

3. What are Sass, Less, and Stylus?

Sass - Sass is the acronym for “Syntactically Awesome Style Sheets”. A ‘$’ sign commonly precedes it.

$font-color: #fff 

        $bg-color: #00f        #box

          color: $font-color

          background: $bg-color

Less - LESS is an acronym for “Leaner Stylesheets”. Less uses ‘@’ to define the variables.

@font-color: #fff;

          @bg-color: #00f          

          #box{

            color: @font-color;

            background: @bg-color;

          }

Stylus - Stylus offers a great deal of flexibility in writing syntax. It doesn’t use @ or $ for defining variables. 

font-color= #fff;

        bg-color = #00f;     #box {

          color: font-color;

          background: bg-color; }

4. Explain Box Sizing Property

Box Sizing property defines how the height and width of a box are calculated. 

Content Box - The default width and height apply only to the element’s content. Padding and border are added outside the box.

Padding Box - You add the dimensions to both element’s content and padding. It adds the border outside the box.

Border Box - The dimensions are added to the content, padding, and border. 

5. What are the different ways to hide an Element using CSS?

display: none

Hides the content and doesn’t store it in the DOM

visibility: hidden

It adds the element to the DOM and takes up space. However, it is not visible to the user

position: absolute

You can make the element appear outside the screen

6. What does ‘Important’ in CSS mean?

The ‘important’ keyword indicates the highest precedence, and it overrides the cascaded property.

                color:blue !important;

            }

            #thing {

                color: green;

             <p id="thing">Will be BLUE.</p> 

7. What are CSS Sprites?

• Since each image sends out an HTTP request separately, a web page with a high number of photos takes longer to load.
• CSS sprites are used to minimize the loading time of a web page by combining multiple small pictures into a single image.
• It decreases the number of HTTP requests and, as a result, the time it takes for pages to load.

8. Which Property is used to Underline, Strikethrough, and Overline Text?

text-decoration

Text-transform

JavaScript Interview Questions

JavaScript is used to add user interaction to an application. The following section targets the commonly asked JavaScript Frontend Developer Interview Questions. 

1. What are the various Data Types in JavaScript?

JavaScript has many data types to provide the basic functionality needed for a web application. They are mentioned in this table. 

2. What is Callback in JavaScript?

A callback is a JavaScript function that is sent as an argument or parameter to another function.

You call this function whenever the function to which it is provided is called.

3. What’s the difference between Function Declaration and Function Expression?

Function declaration .

function abc(){

    return 5;

Within the main JavaScript code, it declares this as a separate statement. It is possible to invoke it before the function has been defined. It provides improved code readability.

Function Expression 

var a = function abc(){

It is created inside an expression or some other construct. It is generally used when there is a need for a conditional declaration of a function. 

4. What do you understand about Cookies in JavaScript? 

A cookie is a little piece of data sent by a website and kept on the user's computer by the web browser that was used to access the page.

Cookies are used to remember information for later use and to keep track of a website's browsing activities.

The simplest approach to make a cookie with JavaScript is to do it as follows:

document.cookie = "key1 = value1; key2 = value2; expires = date";

To delete a cookie, you can just set an expiration date and time; specifying the correct path of the cookie is a good practice. 

function delete_cookie(name) {

      document.cookie = name + "=; Path=/; Expires=Thu, 01 Jan 1970 00:00:01 GMT;";

5. What are Closures in JavaScript?

Closures in JavaScript are a feature where an inner function has access to the outer function’s variables.

function outer_func()

    var b =10;

    function inner_func(){

        var a =20;

        console.log(a+b);

    return inner;

A closure has three scope chains –

• Has access to the variable defined within its curly braces, which is its scope.
• Has access to the outer functions' variables.
• Has the ability to access global variables.

6. What are Imports and Exports in JavaScript?

 export const sqrt = Math.sqrt;

export function square(x) {

  return x * x;

export function diag(x, y) {

  return sqrt(square(x) + square(y));

This file exports two functions that calculate the squares and diagonal of the input respectively. 

import { square, diag } from "calc";

console.log(square(4)); // 16

    console.log(diag(4, 3)); // 5

Here you import those functions and pass input to those functions to calculate square and diagonal.

7. What is the difference between Undefined, Undeclared, and Null in JavaScript?

console.log(x) //Undefined variable

console.log(y) //Null Variable

console.log(z) //Undeclared Variable

Undefined - Undefined means a variable has been declared but a value has not yet been assigned to that variable.

Null - Null is an assignment value that you can assign to any variable that is meant to contain no value.

Undeclared - Variables that are not declared or that do not exist in a program or application.

8. What is the best way to remove Duplicates from a JavaScript Array?

You can delete duplicates from a JavaScript array in one of two ways:

By employing the filtering technique - Three arguments are required to call the filter() function. These are the array, current element, and current element index.

The For loop is used to store all the repeated elements in an empty array.

ReactJS Interview Questions

React is a popular Frontend JavaScript library. It is vital to have a good understanding of a JavaScript framework or library for app development. 

The following segment of Frontend Developer Interview Questions comprises React questions. 

1. What Is JSX?

• JSX is a JavaScript syntactic extension. It's a term used in React to describe how the user interface should seem.
• You can write HTML structures in the same file as JavaScript code by utilizing JSX.
• Because it avoids the use of complicated JS DOM structures, JSX makes the code easier to comprehend and debug.

2. What is Virtual DOM?

• The Virtual DOM is the lightweight version of the Real DOM that React retains in memory.
• Because nothing is drawn on the screen when processing Real DOM, it is substantially slower than handling virtual DOM.
• When an object's state changes, Virtual DOM updates only that object in the real DOM rather than all of them.

3. What are React Extensions? Name a few of them.

• React is more than just a UI framework; it contains a slew of extensions that cover the entire application architecture.
• It has a server-side rendering feature.
• Supports the creation of mobile apps.
• Flux and Redux, among other things, have been added to the mix.

• Flux is Facebook's application architecture for developing online applications.
• React Native allows you to create mobile apps entirely in JavaScript.

4. What is an Event in React? How do you create one?

An event is an action triggered by the user or any system event, like pressing a key, a mouse key, etc. 

5. What are Components in ReactJS?

Components are the building blocks of a React application that represent a part of the user interface.

• A component used in one area of the application can be reused in another area. This helps speed up the development process.
• A component can contain several other components.
• A component must define a render method that specifies how the component renders to the DOM in its minimal form.
• A component can also receive props. These are properties passed by its parent to specify values.

6. What is a State in React? How do you implement it?

A state is an object that stores the values of properties belonging to a component that could change over a period of time. 

Here are a few features of a State - 

• You can change a state as a result of a user's action or changes in the network.
• React re-renders the component to the browser whenever the state of an object changes.
• You initialize the state object in the constructor.
• It can store multiple properties in the state object.
• this.setState() is used to alter the state object's value.
• The setState() function merges the new and old state and the previous state in a shallow merge.

7. What is a Higher Order and Pure Components in React?

Higher order components .

• A higher-order component is a function that takes a component and returns a new component.
• It facilitates reusing of component logic.

 const NewComponent = higherOrderComponent(originalComponent)

Pure Components 

• React.Component is the base class for React components. React.PureComponent is a variation of React.Component class and does a shallow comparison of props and state.
• A React component can be considered pure if it renders the same output for the same state and props.

8. How do you Implement React Routing?

Considering that you have the App, About, and Contact components, routing can be implemented using the code shown above. 

Angular Interview Questions 

If you are well versed in the Angular Framework , then these Frontend Developer Interview Questions on Angular will be helpful. 

Also Read: How to Learn Angular: Benefits of Angular and Certifications

1. What is Data Binding and how does it work? Which Data Binding methods does Angular use?

Data binding is a method of manipulating web page elements through the usage of a web browser. It's utilized in interactive elements like forms, calculators, tutorials, and games on web pages.

Two-way Data Binding is used by Angular. Any modifications made to the user interface mirror the elements in the model state and vice versa. 

2. What is Typescript? 

TypeScript is an object-oriented programming language that is a superset of JavaScript. Simply put, it's JavaScript with a slew of other remarkable capabilities. All TypeScript code is eventually compiled to JavaScript.

• TypeScript supports all JavaScript libraries and frameworks, to name a few essential characteristics. Angular is a single-page application framework written in JavaScript.
• With the rise in code complexity, JavaScript needed to meet OOP's criteria, which led to the creation of TypeScript.
• TypeScript aids in the production of faster code, which improves performance.

3. What is AoT Compilation? How is it different from JiT? 

Ahead of Time (AOT), compilation translates your code as it is being built, rather than when it is downloaded and run by the browser. This guarantees that the browser renders content quickly. Include the —aot option with the ng build or ng serve commands to specify AOT compilation. 

The Just-in-Time (JIT) compilation technique converts computer code to machine code while it is being executed or run. Dynamic compilation is another name for it. When you use the ng build or ng serve CLI commands, by default it uses JIT compilation.

4. What are Pipes in Angular? Explain its types

Pipes are simple functions that accept an input value, process it, and return an altered value as an output, in a more technical sense. Angular has several built-in pipes. You can, however, make custom pipes to meet your specific requirements.

The following are some major features:

• The pipe "|" symbol is used to define pipes.
• Pipes can be linked together in a chain.
• The colon (:) sign can be used to provide arguments to pipes.

Pure Pipes 

These are pipes with just pure functions. As a result, a pure pipe uses no internal state, and the output remains constant as long as the parameters provided remain constant. When Angular detects a change in the arguments being given, it invokes the pipe. Throughout all components, a single instance of the pure pipe is used.

Impure Pipes 

Angular calls an impure pipe for every change detection cycle, independent of the change in the input fields. For these pipes, it produces multiple pipe instances. The inputs to these pipes can be changed.

All pipes are pure by default. On the other hand, the pure attribute can be used to identify impure pipes, as demonstrated below.

  name: 'demopipe',

  pure : true/false 

export class DemopipePipe implements PipeTransform {

5. In Angular, what are Promises and Observables?

While both concepts in Angular deal with asynchronous events, Promises deal with one at a time, whereas observables deal with a sequence of events over time.

• Promises are objects that emit only one value at a time. They go into effect right once they're created and can't be stopped. They are Promises to the child Push Errors.
• Observables - Observables are only executed when the subscribe() method is used to subscribe to them. Over a period, they emit multiple values. They aid in the execution of tasks such as forEach, filter, and retry, among others. Subscribers receive errors as a result of their actions. The listener stops receiving new data when they perform the unsubscribe() method.

6. What are Form Control and Form Groups?

Form control .

• It enables validation through the Form Control class.
• It produces a new instance of this class for each input field.
• These instances allow you to verify the field's values to see if they've been touched, untouched, or dirty.

• A group of controls is represented by the FormGroup class.
• Multiple control groups are possible in a form.
• If all the controls are valid, the Form Group class returns True.
• It also includes a list of all validation problems.

7. What is Eager and Lazy Loading?

Eager loading - The default module-loading approach is eager loading. Eager loading feature modules are loaded before the program starts. You usually reserve this for applications that aren't too large.

Lazy Loading - When there is a demand, lazy loading dynamically loads the feature modules. This speeds up the application. It's utilized in larger applications where all the modules aren't required right at the start.

8. In Angular, what is String Interpolation?

String interpolation is a one-way data-binding method that delivers data from TypeScript code to an HTML view. Double curly braces are used to indicate it. This template expression allows the data from the component to be displayed in the view.

Generic Interview Questions

Not all questions will be core technical. The interviewer would also like to understand your take on certain Frontend related questions or suggestions. The last segment of the Frontend Developer Interview Questions article focuses on some generic questions. 

1. What are the Advantages of TypeScript Over JavaScript?

• TypeScript points out compilation errors during development.
• Supports strongly typed and static typing.
• Better features like interfaces, generics, and more.
• Provides excellent tooling support with IntelliSense.

2. How is a Web Developer different from a Web Designer?

3. what is backend development.

Web development that occurs at the back end of programs is accurately termed back end development. Back-end development covers server-side web application logic and integration and activities, like writing APIs, creating libraries, and working with system components instead of frontend development, which focuses on customer-facing services and programs. Back-end developers build code that allows a database and an application to communicate with one another. Backend developers are in charge of the back end of a website, which includes servers, databases, and apps, and they control what you don't see.

Also Read: How to Become a Backend Developer?

4. What is CoffeeScript?

• CoffeeScript is a JavaScript-compiling programming language.
• It's an attempt to demonstrate the positive points of JavaScript straightforwardly.
• It also makes it easier to develop JavaScript code by providing a more consistent syntax and avoiding the peculiarities of the JavaScript language.

5. How would you ensure a web design is user-friendly?

• A frontend developer should work closely with the user experience team to visualize the design for the app.
• They should also test the web application and take user inputs.
• The app developed should be compatible with different platforms and must ultimately run smoothly on the mobile phone.

6. Would you recommend a Web Designer Role or a Web Developer Role?

It is really a matter of preference. 

• If you are inclined towards the creative aspect, you should go for a Web/UX Designer role. 
• If you are inclined towards the coding aspect, you should go for the Web Developer role.  

7. How would you increase Page Performance?

• You should clean the HTML document up
• External HTTP requests could be minimized
• Sprites, compressed images, and smaller images can be included
• At the bottom of the page, include the JavaScript
• Optimize CSS, JavaScript, and HTML
• Caching and CDN

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Front End Developer Interview Questions: What to Ask and Expect

Are you a Front End Developer seeking a job in one of the top US MNCs? Or, are you a recruiter from a top US MNC looking for an excellent Front End Developer ? In either case, you have landed on the right page.

Table of Contents

Front-end developers are in high demand, and the outlook for this position is improving as more companies adopt various technologies. According to the U.S. Bureau of Labor Statistics , this position is expected to grow by 23% in the next decade, which is faster than the average growth rate across the workforce.

If your company is in the market for hiring front-end developers , you may find yourself hosting multiple interviews. But human resources professionals doing initial job screenings may not be familiar with the intricacies of the position. Here are some common front-end developer interview questions and potential answers. By becoming familiar with these questions and the correct answers, your recruiting team can conduct successful front end interviews to move the most qualified candidates through the process.

Front-End Development Core Concepts

Whether you have a need for experienced developers or are filling out your team with some green talent, you will need to ask some baseline questions to help ensure that each applicant fits into developer role. These are some common interview questions that any applicant may expect regardless of their credentials.

Basic Front End Developer Interview Questions

Ask these questions to get a sense of each applicant’s overall skills:

• What excites you most about front-end development?
• What are the must-haves when creating a user-friendly, accessible website or mobile app?
• How have you used HTML5 in previous projects?
• How do you choose which programming language to use when developing a website or app?
• What are the main differences between CSS and JavaScript, and when would you use them?

What Excites You Most About Front-End Development?

This answer will vary from person to person, but it will help you get a sense of their enthusiasm. With this answer, you can build an understanding of who might fit into your project team and who might not align with your goals and mission. It also gives you a sense of how they would fit into the job, particularly if their favorite part of developing is something they won't be doing regularly.

Must-Haves for Creating a User-Friendly, Accessible Site

Although each potential front-end developer will likely have a different answer to this question, it gives you a sense of their approach to design. At any level, a front-end developer needs to understand how their designs impact end users. They should be familiar with best practices throughout software development . Commonly, user-friendly and accessible websites include these features:

• Organized logically
• Easy to navigate
• Responsive design
• Includes features that improve the experience for people with disabilities that impact their vision, hearing, or movement

How Have You Used HTML5?

HTML is the primary language used to design and program websites. HTML5 offers additional functionalities, giving front-end developers more options, like building offline applications. This language allows developers to build a site that doesn’t rely on cookies to store temporary data, embed audio and video into web pages without using plugins, and build a site with simple syntaxes, among others functions. If you’re interviewing front-end developers, they should know how to use it, even if they’re new to the field.

How Do You Choose Which Programming Language to Use?

There are many different programming languages that control different parts of a website, computer program, or mobile application. Common languages include CSS and JavaScript. CSS , which stands for Cascading Sheet Styles, is used to create design elements of a website like fonts, colors, and layouts. It’s also the language programmers use to enable a site to load on a mobile device without losing its functionality.

On the other hand, JavaScript governs the nonstatic features of any website. This includes any element that goes beyond a simple landing page with text and images. JavaScript controls chat bot popups, video, automatic refreshers, interactive maps, and more.

Entry Level Front-End Developer Interview Questions

Once you’ve established a candidate’s overall experience with common front-end development concepts, you can start refining questions based on their job level. Here are some common questions and answers for a front-end interview when a candidate has little to no practical experience.

• What are the most important skills for a front-end developer?
• What are HTML meta tags?
• What is load balancing?
• What is the difference between JavaScript and jQuery?
• Write code using HTML5 and CSS for a product landing page

What Are the Most Important Skills for a Front-End Developer?

The “correct” answer to this question might vary based on your needs. You may program in a specific language in which you want your developers to be proficient. But here are some common programming skills and soft skills you may consider:

• JavaScript/jQuery
• Testing/debugging
• Problem solving
• Communication skills

What Are HTML Meta Tags?

Meta tags go inside the head tag of an HTML webpage. They enable browsers to find metadata related to a website. Meta tags can include any type of information you want to include to make your site easier to find such as keywords, descriptions, and more. You can also use a meta data tag to indicate when your site was last updated or to program your webpage to automatically refresh.

What Is Load Balancing?

Load balancing refers to how incoming traffic is distributed among back-end servers. It’s important because there are billions of people navigating the internet every day. With so much potential web traffic, your site could easily get bogged down by too many users. Load balancing helps you keep your page responsive regardless of how many visitors are there.

What Is the Difference Between JavaScript and jQuery

JavaScript is a programming language and jQuery is an interface used to program applications. jQuery helps simplify the process of writing code making it easier for front-end developers to design and program a website quickly.

jQuery is a library of existing JavaScript frameworks that keep front-end developers from having to rewrite every piece of code when they’re trying to build elements of a website or an app.

Write Code Using HTML5 and CSS for a Product Landing Page

This question is an example of a task you can use to assess a new candidate’s skill level. Tailor it to your own business and tasks you ask of your software development team. You can either have the interviewee write code with the interviewer, or you can assign it as a take-home task. Giving a candidate “homework” is a good way to assess how they respond to challenges and how long it takes them to complete a task with minimal oversight. It’s a great way to assess potential remote workers.

Advanced Front End Developer Interview Questions

When you’re interviewing more advanced front-end developers, you likely have a specific project role in mind. So you’ll probably spend a lot of your interview time asking questions related to your specific platforms and project needs. However, there are some common interview questions you can ask of your more experienced developers.

Basic Interview Questions for Advanced Front End Developers

Use these questions to better understand a candidate’s skill level and assess how well they would round out your project team:

• How do you organize class modules and assets?
• How would you find a bug in an application
• What is CoffeeScript?
• When would you use CoffeeScript over JavaScript?
• Tell me about your favorite project and what made it your favorite.

How Do You Organize Your Code?

Seasoned front-end developers have different preferences for organizing code. How a candidate answers this question will help you determine their personal style, and you can use it to see if they’re flexible about their methodologies. Common ways to organize code are by tags, by programming language, or by asset type.

Learning how a potential developer organizes code will give you an understanding of how much training they may need to start working on your projects. It also offers insight into their thought process. You could follow this question up with a “why” to assess your candidate.  

How Would You Find a Bug in an Application?

Even seasoned software developers run into bugs and application malfunctions. Finding and fixing them is a common task for your team. Ask this question to learn about how a potential new hire tests for bugs. Anyone who’s been in front-end development for a while will probably have a few examples where they had to find complicated bugs.

Ask your candidate to share some of these cases and what they did to successfully resolve the problem. Through this question, you’ll get a sense of their problem-solving skills and how they react under pressure.

What Is CoffeeScript?

CoffeeScript is a programming language that helps you write better code in JavaScript without having to write long strings of code. You can use it to write parts of your code in a shorter way, and the program then converts your shorthand code into JavaScript. Like jQuery, this tool helps software developers work quickly.

When Would You Use CoffeeScript Over JavaScript?

CoffeeScript gives you cleaner code than JavaScript without taking away functionality. You can write code with simpler commands, and you don’t have to include symbols, which makes this language easier to write. It’s easier for other programmers to maintain and build because they don’t have to wade through long strings of code to modify a program.

If you have multiple team members working on a single project, CoffeeScript can potentially make it easier for them to collaborate on different parts of the app or the website.

Tell Me About Your Favorite Project and What Made It Your Favorite

Letting a candidate tell you about a case study is a good way to determine their passions. You learn about which parts of their job they like best, because these are what they choose to highlight. Asking why they chose a certain project tells you about their strengths. Your potential candidates will likely tell you about projects they feel like they did well, so you get a better sense of how they view themselves than you would if you just asked them to identify their strengths and weaknesses.

Basic Interview Questions to Assess Soft Skills

If you’re hiring seasoned professionals or candidates fresh out of college, you will likely need people who have a variety of soft skills like problem-solving and communication. These skills become even more important if you’re planning on hiring remote workers. Not everyone is cut out to work in a fully remote environment, and it’s better to get a sense of this in the interview.

These questions can help you assess a candidate’s soft skills:

• Explain your job to a person who’s been living under a rock.
• What is your preferred communication style?
• How do you collaborate with colleagues in a remote setting?
• Discuss a project that wasn’t successful and how you managed the challenge.
• Talk about a time you went above and beyond your normal job.

Explain Your Job to a Person Who’s Been Living Under a Rock

A candidate’s answer to this question not only helps you assess how well they understand their job, it also tests their creativity and their ability to think on the fly. Asking your interviewees to distill their job into the simplest terms gives you an idea of what they consider the most important parts of their job. Because under pressure, they’ll probably leave a few things out.

What Is Your Preferred Communication Style?

Ask this question to see how a potential candidate may fit into your team. You may have a team of developers who like hosting video conferences once a week to collaborate and discuss progress on each project. If the person you’re interviewing would rather receive texts or emails, they may not fit in with your team. On its own, this isn’t a reason to pass over a candidate, but it helps you anticipate potential modifications you might need to make to your processes.

How Do You Collaborate With Colleagues in a Remote Setting?

You may have software developers in various locations who need to work closely on projects. This question will help you gauge a new recruit’s comfort level with remote work. You could follow up and ask how they build a team in a remote environment and what they do to stay motivated when they’re not in an office setting.

Discuss an Unsuccessful Project

Asking someone to expand on their failures gives you a sense of their willingness to accept responsibility for problems. It’s also a great way of learning about a candidate’s problem-solving skills. Ask how they managed conflict with their teammates and how they contributed to the resolution.

Tell Me About a Time When You Went Above and Beyond Your Normal Job

This is a behavioral question that you can use to see how a potential new employee would fit into your team. It also shows you if they’re willing to pull their weight when your team is in a tough spot.

Front-End Developer Recruiting Challenges

Like other industries, software development is experiencing a shortage of experienced workers. But this isn’t the only challenge facing recruiters when trying to hire front-end developers. One such challenge is that software engineering programs may not have the same curriculum, so you can’t be sure that a candidate has the skills you need.

You can overcome this challenge by hiring people who are adaptable and learn quickly. A new developer may not need to be an expert in certain skills if someone on your team takes the time to train them. You can also send them to a bootcamp program to brush up on some of the skills they’re lacking.

Software development has been affect by the development shortage . But you can address this challenge by widening your pool and building a remote team of workers from various countries. However, you may not be the only company with this idea, which leads to the next recruiting challenge — competition.

There is fierce competition among employers for the best and brightest software developers. You may need some help to brand your company in a way that stands out among potential applicants. Offer cues to your company’s culture through your website and social media. And clearly identify what makes you a great employer.

Finding the Right Front-End Developers for Hire

Whether you’re using an HR team to screen candidates or you’re conducting each round of interviews yourself, you need a consistent set of questions, including those covered here. Ask a mix of basic questions related to the job and those that help you assess soft skills like problem-solving and collaboration. Include some specific questions tailored to the position, specifically if you need someone who is experienced with certain programming languages.

Once you’ve posted your job description, make a list of questions, and ask the same set to each candidate. The conversation will probably deviate but keeping your questions consistent makes it easier to compare candidates. You could keep a spreadsheet with key points to help you decide whom to move forward with through the process. If you are interested in saving your company time and energy on finding the right front-end developer, we encourage you to start with Revelo. Revelo will help with all of your nearshoring needs, and get you matched with the right candidates so that you can fill the roles quickly and efficiently.

Further Resource:  Alternative Tech Staffing Platform

Why Choose Revelo?

Quick turnaround for candidate shortlists

A vast talent pool of 
pre-vetted developers

Professional sourcing, vetting, and onboarding support

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Code Clause Work Experience For Frontend Developer Intern

Introduction.

Entering the realm of software development, I embarked on a transformative journey as a front-end software developer at CodeClause. With a toolkit comprising HTML, CSS, and JavaScript, I delved into a world where creativity meets functionality, crafting an array of projects ranging from e-commerce platforms to music websites and portfolio showcases. Beyond the code, this internship was a crucible for personal and professional growth, refining skills in leadership, time management, and collaborative learning.

Diving into Development

At CodeClause, every day presented new challenges and opportunities. Armed with foundational knowledge and a thirst for innovation, I immersed myself in the intricacies of frontend development. From structuring web pages with HTML to styling them elegantly with CSS, and finally, breathing life into them with JavaScript, each line of code was a brushstroke on the canvas of digital creation.

Building Block by Block: Projects Galore

The heart of my internship experience lay in the projects I undertook. Each project was not merely a technical exercise but a testament to creativity and problem-solving. From designing intuitive user interfaces for e-commerce websites to curating seamless experiences for music enthusiasts, and crafting captivating digital portfolios, every project was a testament to my evolving skills and passion for frontend development.

Learning Beyond Code

Yet, the essence of my internship transcended beyond the lines of code. It was a journey of self-discovery and skill enhancement. Collaborating with colleagues provided invaluable insights and perspectives, fostering an environment of continuous learning. As I navigated through complex tasks and tight deadlines, I honed my time management skills, learning to prioritize effectively and thrive under pressure.

Mentorship: Guiding Lights

Central to my journey at CodeClause were the mentors who served as guiding lights, illuminating my path with wisdom and support. Their expertise and encouragement empowered me to push boundaries and exceed expectations. Whether providing constructive feedback or offering invaluable advice, their mentorship was instrumental in shaping my growth as a front-end developer.

Recognition and Beyond

As my internship drew to a close, the culmination of my efforts bore fruit in the form of recognition and accolades. A coveted offer letter stood as a testament to my contributions and potential within the organization. Additionally, receiving a letter of recommendation and completion certificate served as a testament to my dedication and accomplishments during my tenure at CodeClause.

Conclusion: A Journey of Growth

My internship at CodeClause was more than just a professional stint; it was a transformative journey that enriched me both professionally and personally. Through hands-on projects, collaborative learning, and mentorship, I not only honed my technical skills but also cultivated essential soft skills vital for success in the dynamic world of software development. As I step forward into the next chapter of my career, I carry with me the lessons learned and experiences gained, grateful for the invaluable opportunity to contribute to the innovative endeavors at CodeClause.

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Transforming The Relationship Between Designers And Developers

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About The Author

Chris is a developer, designer, and former digital agency owner. He aims to craft with conscience, create magical customer experiences, and consume as many … More about Chris ↬

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In the forever-shifting landscape of design and technology, some rare artifacts surprisingly never change.

Throughout the last two decades, we have witnessed the astonishing evolution of creative tooling, methodologies, and working practices. However, after all of this advancement, we still have clients asking to make the logo bigger, designers despairing as their creations are built with not quite the exact amount of bottom-margin, and developers going crazy about last-minute design changes.

Quite frankly, I’ve had enough . So join me in a parenting-style-hands-on-hips pose of disdain, roll up your sleeves, and let’s fix this mess together, once and for all!

Why Is This Still An Important Topic?

Ultimately, the quality of your designer-developer relations will have a vital impact on the quality of your product. In turn, this will impact customer experience (be it internal or external).

Customer experience is everything, and these days the smallest of chinks can create an even bigger dent in the business itself.

It may not even be an obvious or noticeable issue. Over time, those moments of misunderstanding in your team could result in a series of micro-inconsistencies that are felt by the customer yet sneak underneath the radar of quality assurance.

Perhaps you’ll catch these things during user research, but in this scenario, you’d be playing catch-up instead of advancing forward.

To cut a long story short, it could be slowing you down in the race against your competitors and costing you more money in the process.

So, with that in mind, let’s get stuck into the techniques that can steer us in the right direction and inspire everyone on the team to deliver the slickest of user experiences together.

Working Culture

In my opinion, process improvements may only get you so far. The working culture in your organization will heavily influence the output of your digital teams. Whilst the subject of culture is incredibly vast, there are a few key elements that I think are hugely important to foster a greater level of collaboration between design and developers:

• Alignment on the goals of the project and/or business.
• Encouraging a more “robotic” attitude to feedback. Of course, you can be passionate about what you do, but when it comes to feedback, I always try to encourage people to respond with logic before emotion.
• Communication : Ultimately, you have to trust people to be proactive. You can have a great process, but the gaps and edge cases will still slip through the net unless you have people who are open and ready to prod each other when issues arise.

This may seem like common sense to many of us, but many organizations (big ones, too!) still operate without this crucial foundation to motivate and support their teams.

However, it is essential to be honest with yourself and consider the role you play within your team. Even if you think you have already fulfilled these criteria, I’d encourage you to investigate this further to ensure everyone feels the same. It can be as simple as having a 121 discussion with each member of the team, or you could even send out short questionnaires to gauge your workplace’s suitability for an optimal designer and developer collaboration.

You might be surprised by what you hear back from people. Treat any criticism as gold dust. It’s an opportunity to improve.

Once you’ve created this foundation within your organization, it’s important to maintain and protect it. Keep reviewing it regularly, and make sure that anyone joining the team will be able to fit in. This leads us nicely on to…

If you’re scaling your team, maintaining quality can always be a challenge as you grow. Despite the challenges, it’s important to continue hiring people who have a positive and empathetic attitude to ensure you can maintain this foundation within your workplace.

In order to gauge this, I would like to include the following interview questions.

Begin by showing a sample screenshot of your product or a specially crafted concept design:

“You’ve just built X, and the designer wants to change Y. How do you respond?” Follow up: “The designer and PM reject your suggestion because of _______. How do you respond?”

“The developer says, “We can’t build X quickly; can we do Y instead to deliver faster?” How do you react?” Follow up: “The product owner says they are then disappointed with the design. How do you react?”

I recommend asking these kinds of questions in the middle or towards the end of the interview so you have already built rapport. If the candidate is at ease, they are more likely to let slip any negative attitudes that lurk beneath the surface.

I’ve asked interview questions like these to many designers and developers, and every so often, they will openly criticize and stereotype each other with a smile on their faces. I’ve even seen some candidates become visibly frustrated as they recount real-life scenarios from their own experiences.

How you score this is more difficult. Ultimately, skills and work ethic are the most important things , so concerning answers to these questions may not necessarily lead to an outright rejection but perhaps flag something you may need to work on with the candidate if they do later join your team.

Hopefully, in most cases, the stronger candidates you speak to will naturally provide balanced and conscientious responses to these tests of character!

We talked a bit about hiring, but I’d imagine many people who need this article are more likely to be in the midst of a designer-developer flame-war as opposed to trying to prevent one in the future!

So, what can we do process-wise to keep things flowing?

Provided that there is plenty of early and ongoing collaboration in your workflow, there is no absolute right or wrong answer. It’s about what fits your team and your product best. Ultimately, you need to discard the silos of the past and start working together as a team early on.

• Developers would typically be the last people to get involved, but they should be involved from the start to guide technical feasibility and provide their own ideas.
• Designers are often more involved in the beginning but can often drift away before the end of a release. However, we need to keep them onboard and get them to play with the product so we can keep making it even better!

It’s important to be open-minded about the solutions. Alas, I have even worked in organizations where different teams have different approaches. Bearing that in mind, here are some good places to start in terms of exploring what might work for your workplace.

When new features are on the horizon, getting everyone involved in these discussions is crucial.

Sometimes, it can be difficult for developers to detach from the current sprint and think ahead, but it’s important that we have their guidance, and it is ultimately going to save them (and the whole team) time further down the line.

Scoping can appear in many different forms across the spectrum of agile methodologies out there. It’s not my intention to cover any of these and discuss all the positives and negatives of each (that’d make this into a book, and not one that anyone would like to read!); in fact, I am deliberately not mentioning any of them. This article is ultimately about people, and the people we need at this early stage are not just the stakeholders and a product manager. We need designers and developers shaping these early discussions for the following reasons:

• They will bring their own ideas.
• They will visualize the idea very quickly and assess its feasibility.
• They will connect the concept with other parts of the domain.
• They will also (albeit rarely!) prevent an impossible dream or daft idea from growing on the face of the business like a festering wart.

Another Perspective On Scoping: SquaredUp

In order to take a deeper dive into the subject of scoping, I spoke to Dave Clarke, product manager at SquaredUp .

“Developers are looped in during the design stage, and we’ll test interactive mockups with the engineering team as well as other internal stakeholders before going out to external audiences for feedback. This means that when a feature is ready to be built by an engineer, they’re already really familiar with what we’re building” — Dave Clarke

Back in late 2018, I met the SquaredUp team at an open day in their UK hub in Maidenhead. I was impressed by the quality of their product, considering it was a very technical audience. It looked beautiful, and you could tell that they went the extra mile in terms of collaboration. Not only do they involve developers in the design phase, but they get them involved even earlier than that.

“We send engineers to events so they can talk to customers and hear their pain points first-hand. This helps foster a real appreciation and understanding of the ‘user’ and ensures designers/developers/PMs are all coming at a problem with a solid understanding of the issue from the user’s perspective.” — Dave Clarke

This brings us back again to that all-important foundation. Alignment on goals is key, and what better way to reinforce that message than by getting everyone involved in hearing directly from the end users of your product?

Design Presentations

Once the wheels are in motion on the big new thing, many teams like to have the designer present their work for forthcoming iteration(s) to the team. This allows everyone to have a say and get excited about what is coming up.

Once again, there are many organizations that would simply agree on the design between stakeholders and designers alone. From the developer perspective, this is incredibly frustrating. Not only will it result in a lower-quality output , but it will also make developers feel as though their opinion doesn’t matter .

With my developer hat on, though, I absolutely love these kinds of sessions. They allow us to question the details, suggest alternatives, and consider how we slice stuff up into smaller bundles of value that can be released faster.

With my design hat on, it caters to my need to think about the bigger picture. It’s not always practical to design iteratively, but in these sessions, we can all get together and appreciate the end-to-end experience .

Typically, we allow the designer time to talk through everything, allowing for questions throughout, and give everyone a chance to dive in and bring their ideas to the table. However, do what works for your team. If you have a designer who wants to present, take all questions at the end and then make changes afterward, do that. If you have one who likes handling lots of questions throughout and makes changes live, go with that.

Perhaps even give it your own identity, too. In my current workplace, one of the squads calls it Design Time and in our squad, we decided to open the name to a poll, and thus (with one cheeky addition to the poll from a colleague) the Itty Bitty Refinement Committee was born!

Managing Conflict

However, these kinds of sessions do have the potential to get sidetracked . So, as with any meeting, it is essential to have a clear agenda and ensure that good facilitation prevents things from going off-piste. If there are conflicts, I always try to find resolutions by considering where we might find the answers. For example,

• Can we look at our analytics?
• Which option is a better fit for our company goals?
• Could we do an A/B test to see what is more effective?

When people bring ideas to the table, it’s always important to acknowledge them positively and seek further exploration . Sometimes, we can agree on an approach quickly, and on other occasions, we can defer the discussion to a later refinement session.

Sharing Responsibilities

In my opinion, there is also a gray area between designers and developers, where it often isn’t clear who holds responsibility. This is a big risk because, in many organizations, essential aspects can be completely forgotten.

From my past experience, there are two key areas where I see this happening often. So this may not be exhaustive, but I encourage you to think about these and then ask yourself: Is there anything else — specific to my organization — that could have fallen into this void between our designers and developers?

See if you can identify these risks and agree on a way of working together to ensure they are tackled effectively.

Nowadays, many dev teams are working on JavaScript-heavy applications, and most of us will have the power of CSS transitions at our disposal. Yet, I frequently land on new projects where they aren’t being leveraged to enhance the customer experience.

Animations can be quite time-consuming to create using many design tools. In particular, I often find that loading states are quite fiddly to prototype in some cases.

In my recent work at Floww , I collaborated with designer Hidemi Wenn on an animated progress bar. For the first version, Hidemi had begun with an idea crafted in After Effects. I replicated this in a CodePen and suggested adding some bubbles to highlight the changes in the numbers.

Note : Of course, CodePen is just one example of this. There are many other tools out there, such as Storybook, that can also allow us to build and collaborate on ideas quickly.

See the Pen [Bar Chart of Destiny [forked]](https://codepen.io/smashingmag/pen/abrOJBr) by Chris Day .

This allowed Hidemi to see her creation working in the browser early — before it had been fully implemented into the product — and we then collaborated further to make more enhancements.

“Working together like this was awesome! We could easily bounce around ideas, and tweaking the animation was a breeze.” — Hidemi Wenn, Product Designer at Floww

Pairing is often between developers, but why not jump on a call and pair with a designer whilst you write the CSS? This gives them full transparency, and you can collaborate together. “

Nowadays, we have amazing tools at our disposal to collaborate, and yet still, so many designers and developers elect to operate in silos.

Accessibility

One of the first things I do when joining any existing digital project is to spin up Wave (an accessibility testing tool) and subsequently slump into my seat in despair.

Accessibility is something that always suffers as a result of a designer/developer standoff. Some might say it’s the realm of design, while others would argue it’s quite a technical thing and, therefore, lives in dev land. The truth is it is a shared responsibility .

Take something like :focus , for example. Whenever I review code, this is something I always check and often discover it’s missing. Ask the developer, and they’ll say, “We didn’t have designs for it.” Well, perhaps, ask the designer to create them, just as I’d expect the designer to query an unimplemented state they had designed for.

We should scrutinize each other’s work and continue to channel our inner robot to respond with logic when it comes to constructive criticism. Keep encouraging everyone to embrace feedback because that is the gold dust that makes our product shine brighter. “

During Implementation

Having steered our way together through the implementation of our features, at some point, we begin to approach the time to release our features into the wild. We are on the final stretch, and thus, it’s time for developers to stage a reverse-design presentation!

Whilst mentoring developers on this subject, I always remind them not to take the feedback personally .

Likewise, I ask designers to never hold back . Be persnickety (in a kind way!) and ensure all your concerns are addressed.

It’s only natural for a developer to behave defensively in these scenarios. As a result, designers may hold back on some of the feedback they provide in order to prevent upsetting the developer.

Developers are often very vocal, and if you are tasked with delivering a barrage of design feedback to them, it can appear daunting and make designers fearful of a backlash.

Prevent the silo. Perhaps have a third party , such as the product owner/manager, attend the meetings. They can diffuse any situation by referring us all back to the business value.

I’ve also witnessed rare cases where the developer has nodded and agreed with all the feedback and then just hasn’t implemented any of it afterward! So, make sure it’s all captured in whatever project management tools you use so you can follow up on the status. Sometimes, it’s easy to forget to do this when the changes are so small, so often (in my current team), we might create a single ticket on our board to implement all the feedback changes as opposed to creating a work item for each.

Another common issue I’ve found is that I’ve met many designers who don’t actually ever test out the products that they design . For me, they are missing out on the opportunity to further hone their work, and to learn.

If you’re a designer, ensure that you can log in to the app/website. Get a test account from someone, and try to break stuff !

Once all the feedback is in, we can create more work items to give our product those magical finishing touches and ship our masterpiece to the World.

Design Systems

Having mentioned focus states earlier on, you were probably already thinking about design systems before this heading came along! Of course, the design system plays a key role in helping us maintain that consistency, and ensuring accessibility concerns are baked-in to our library of beautiful components.

There are many, many articles about design systems out there already but here, I am going to just consider them in the context of the working relationship.

As the design system encourages reuse, it encourages us to think about other teams in our organization and be more mindful.

If the basic building blocks are covered, we can focus on solving more complex challenges together. I think this is also a really important value to get your teams on board with.

Design systems can also cause friction. Not everyone will get on board with it. Some designers will feel as though it restricts their creativity. Some developers will be frustrated at having to update the design system instead of cracking on with their own features.

In my opinion, these attitudes will not only slow you down but could harm the working culture of your business. Nowadays, I’d say it’s absolutely crucial for any product team (big or small) to have a design system and have the majority of your team buying into it.

I’ve been present at organizations where the design system is neglected, and in these cases, it actually ends up worse than not having one at all. You really need the majority of your team to be committed to it; otherwise, some people will go off-piste and keep reinventing the wheel (probably without those focus states!).

Another Perspective On Design Systems: GOV.UK

The GDS (Government Digital Service) of the UK has built a design system that serves a vast spectrum of different services and tech stacks. An enormous challenge, which is almost certain to be of interest in our quest for knowledge! So, I got in touch with product designer Ed Horsford who has worked on a series of government services that make use of this.

“GDS provides the GOV.UK Prototype Kit , so as a designer, I can create something in the kit, make full use of the functionality of the design system, and point developers towards the prototype.” — Edward Horsford

Whilst many other organizations are now making use of tools such as Figma’s excellent Dev Mode feature to streamline design handover, this still requires naming conventions to be lined up between the codebase and the Figma component library. What’s impressive about GDS’ approach here is that the provision of their own prototyping tool makes it absolutely clear to developers which components need to be used . However, the availability of a great design system tooling doesn’t always guarantee a smooth outcome, as Ed explains:

“It can be a bit of a mind-shift for developers new to the UK government or using design systems in general — they may default to hand coding the HTML and CSS to match a design, rather than using the components from the design system to match the prototype.” “If there is a bespoke requirement outside of the design system, then I will always call it out early so I can discuss it with the team.” — Edward Horsford

Once again, this takes us back to the importance of communication. In a landscape where a design system must be deployed amongst many different teams, it’s up to the designers and developers to scrutinize each other’s work .

It was great to hear that as a designer, Ed was actively looking at the front-end code to assist the developer, ensuring the design system was respected so that all of its many benefits could be embedded into the product.

Crisis Mode

I appreciate that much of the advice in this article requires planning and a fair bit of trial and error. So what do you do if your designers and developers are already engulfed in a mass brawl that needs to be quelled?

In these scenarios, I think it is an ideal moment to pause and simply ask each member of the team: What is our goal? What are we working towards?

If people are angry, in some ways, it’s a good thing because you know they care. People who care should always be open to a bit of a reset. Openly discuss what everyone wants, and you’ll probably be surprised at how aligned people really are ; I always go back to this fundamental and work onwards from there.

Sometimes, we get so tangled up in the details we forget what is truly important.

For every angry team, there are probably many more that just don’t give a crap. For me, this is a far worse situation.

Every problem described in this article could be present. The designers make mockups, the designers build them without question, and everyone gets paid. Who needs to question anything? It’s just a job, right?

Can we really fix this?

Well, in my opinion, you are going to need a much deeper dive into company culture to try and revive that team spirit . I have worked at places like this in the past, and it is very challenging to try and implement solutions when the people are just not bought into the vision of the organization.

Whether this is feasible or not depends on your role and the organization itself. I have walked away from situations like this in the past because I didn’t feel as though the organization was willing to change or even be able to acknowledge the problem.

The dynamic between designers and developers is a subject that has always been of great interest to me, as I’ve worked in both roles as well as being an agency owner.

I’m confident as the years continue to progress, this will become less of a problem as the world of work continues to gravitate towards greater levels of inclusivity, honesty, and openness. The foundations of great company culture are so crucial to ensuring that designers and developers can unite and take on the world side-by-side on behalf of your organization.

For now, though, in today’s fragmented and divided world, you can gain a true competitive advantage by leveraging the power of a harmonious digital team built on the foundations of your organizational values.

Go smash it!

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