- General Questions
- HTML Questions
- CSS Questions
- JS Questions
- Testing Questions
- Performance Questions
- Network Questions
- Fun Questions
- What did you learn yesterday/this week?
- What excites or interests you about coding?
- What is a recent technical challenge you experienced and how did you solve it?
- When building a new web site or maintaining one, can you explain some techniques you have used to increase performance?
- Can you describe some SEO best practices or techniques you have used lately?
- Can you explain any common techniques or recent issues solved in regards to front-end security?
- What actions have you personally taken on recent projects to increase maintainability of your code?
- Talk about your preferred development environment.
- Which version control systems are you familiar with?
- Can you describe your workflow when you create a web page?
- If you have 5 different stylesheets, how would you best integrate them into the site?
- Can you describe the difference between progressive enhancement and graceful degradation?
- How would you optimize a website’s assets/resources?
- How many resources will a browser download from a given domain at a time?
- Name 3 ways to decrease page load (perceived or actual load time).
- If you jumped on a project and they used tabs and you used spaces, what would you do?
- Describe how you would create a simple slideshow page.
- If you could master one technology this year, what would it be?
- Explain the importance of standards and standards bodies.
- What is Flash of Unstyled Content? How do you avoid FOUC?
- Explain what ARIA and screenreaders are, and how to make a website accessible.
- Explain some of the pros and cons for CSS animations versus JavaScript animations.
- What does CORS stand for and what issue does it address?
- How did you handle a disagreement with your boss or your collaborator?
- What resources do you use to learn about the latest in front end development and design?
- What skills are needed to be a good front-end developer?
- What role do you see yourself in?
- Explain the difference between cookies, session storage, and local storage?
- Can you explain what happens when you enter a URL into the browser?
- Describe the difference between SSR and CSR. Discuss the pros and cons.
- Are you familiar with static rendering?
- Rehydration?
- What does a
doctype do? - How do you serve a page with content in multiple languages?
- What kind of things must you be wary of when designing or developing for multilingual sites?
- What are
data- attributes good for? - Consider HTML5 as an open web platform. What are the building blocks of HTML5?
- Describe the difference between a
cookie, sessionStorage and localStorage. - Describe the difference between
<script>, <script async> and <script defer>. - Why is it generally a good idea to position CSS
<link>s between <head></head> and JS <script>s just before </body>? Do you know any exceptions? - What is progressive rendering?
- Why you would use a
srcset attribute in an image tag? Explain the process the browser uses when evaluating the content of this attribute. - Have you used different HTML templating languages before?
- What is the difference between
canvas and svg? - What are empty elements in HTML ?
- What is CSS selector specificity and how does it work?
- What’s the difference between “resetting” and “normalizing” CSS? Which would you choose, and why?
- Describe Floats and how they work.
- Describe z-index and how stacking context is formed.
- Describe BFC (Block Formatting Context) and how it works.
- What are the various clearing techniques and which is appropriate for what context?
- How would you approach fixing browser-specific styling issues?
- How do you serve your pages for feature-constrained browsers?
- What techniques/processes do you use?
- What are the different ways to visually hide content (and make it available only for screen readers)?
- Have you ever used a grid system, and if so, what do you prefer?
- Have you used or implemented media queries or mobile specific layouts/CSS?
- Are you familiar with styling SVG?
- Can you give an example of an
@media property other than screen? - What are some of the “gotchas” for writing efficient CSS?
- What are the advantages/disadvantages of using CSS preprocessors?
- Describe what you like and dislike about the CSS preprocessors you have used.
- How would you implement a web design comp that uses non-standard fonts?
- Explain how a browser determines what elements match a CSS selector.
- Describe pseudo-elements and discuss what they are used for.
- Explain your understanding of the box model and how you would tell the browser in CSS to render your layout in different box models.
- What does
* { box-sizing: border-box; } do? What are its advantages? - What is the CSS
display property and can you give a few examples of its use? - What’s the difference between inline and inline-block?
- What’s the difference between the “nth-of-type()” and “nth-child()” selectors?
- What’s the difference between a relative, fixed, absolute and statically positioned element?
- What existing CSS frameworks have you used locally, or in production? How would you change/improve them?
- Have you used CSS Grid?
- Can you explain the difference between coding a web site to be responsive versus using a mobile-first strategy?
- Have you ever worked with retina graphics? If so, when and what techniques did you use?
- Is there any reason you’d want to use
translate() instead of absolute positioning, or vice-versa? And why? - How is clearfix css property useful?
- Can you explain the difference between px, em and rem as they relate to font sizing?
- Can you give an example of a pseudo class? Can you provide an example use case for a pseudo class?
- What is the difference between a block level element and an inline element. Can you provide examples of each type of element?
- What is the difference between CSS Grid and Flexbox? When would you use one over the other?
- Explain event delegation.
- Explain how
this works in JavaScript.- Can you give an example of one of the ways that working with
this has changed in ES6?
- Explain how prototypal inheritance works.
- What’s the difference between a variable that is:
null, undefined or undeclared?- How would you go about checking for any of these states?
- What is a closure, and how/why would you use one?
- What language constructions do you use for iterating over object properties and array items?
- Can you describe the main difference between the
Array.forEach() loop and Array.map() methods and why you would pick one versus the other? - What’s a typical use case for anonymous functions?
- What’s the difference between host objects and native objects?
- Explain the difference between:
function Person(){}, var person = Person(), and var person = new Person()? - Explain the differences on the usage of
foo between function foo() {} and var foo = function() {} - Can you explain what
Function.call and Function.apply do? What’s the notable difference between the two? - Explain
Function.prototype.bind. - What’s the difference between feature detection, feature inference, and using the UA string?
- Explain “hoisting”.
- What is type coercion? What are common pitfalls of relying on type coercion in JavaScript code?
- Describe event bubbling.
- Describe event capturing.
- What’s the difference between an “attribute” and a “property”?
- What are the pros and cons of extending built-in JavaScript objects?
- What is the difference between
== and ===? - Explain the same-origin policy with regards to JavaScript.
- Why is it called a Ternary operator, what does the word “Ternary” indicate?
- What is strict mode? What are some of the advantages/disadvantages of using it?
- What are some of the advantages/disadvantages of writing JavaScript code in a language that compiles to JavaScript?
- What tools and techniques do you use debugging JavaScript code?
- Explain the difference between mutable and immutable objects.
- What is an example of an immutable object in JavaScript?
- What are the pros and cons of immutability?
- How can you achieve immutability in your own code?
- Explain the difference between synchronous and asynchronous functions.
- What is event loop?
- What is the difference between call stack and task queue?
- What are the differences between variables created using
let, var or const? - What are the differences between ES6 class and ES5 function constructors?
- Can you offer a use case for the new arrow
=> function syntax? How does this new syntax differ from other functions? - What advantage is there for using the arrow syntax for a method in a constructor?
- What is the definition of a higher-order function?
- Can you give an example for destructuring an object or an array?
- Can you give an example of generating a string with ES6 Template Literals?
- Can you give an example of a curry function and why this syntax offers an advantage?
- What are the benefits of using
spread syntax and how is it different from rest syntax? - How can you share code between files?
- Why you might want to create static class members?
- What is the difference between
while and do-while loops in JavaScript? - What is a promise? Where and how would you use promise?
- Discuss how you might use Object Oriented Programming principles when coding with JavaScript.
duplicate([1,2,3,4,5]);
- Create a for loop that iterates up to
100 while outputting “fizz” at multiples of 3, “buzz” at multiples of 5 and “fizzbuzz” at multiples of 3 and 5 - What will be returned by each of these?
console.log("hello" || "world")
+Front End Developer Interview Questions ★ Front-end Developer Interview QuestionsSkip to main content- General Questions
- HTML Questions
- CSS Questions
- JS Questions
- Testing Questions
- Performance Questions
- Network Questions
- Fun Questions
- What did you learn yesterday/this week?
- What excites or interests you about coding?
- What is a recent technical challenge you experienced and how did you solve it?
- When building a new web site or maintaining one, can you explain some techniques you have used to increase performance?
- Can you describe some SEO best practices or techniques you have used lately?
- Can you explain any common techniques or recent issues solved in regards to front-end security?
- What actions have you personally taken on recent projects to increase maintainability of your code?
- Talk about your preferred development environment.
- Which version control systems are you familiar with?
- Can you describe your workflow when you create a web page?
- If you have 5 different stylesheets, how would you best integrate them into the site?
- Can you describe the difference between progressive enhancement and graceful degradation?
- How would you optimize a website’s assets/resources?
- How many resources will a browser download from a given domain at a time?
- Name 3 ways to decrease page load (perceived or actual load time).
- If you jumped on a project and they used tabs and you used spaces, what would you do?
- Describe how you would create a simple slideshow page.
- If you could master one technology this year, what would it be?
- Explain the importance of standards and standards bodies.
- What is Flash of Unstyled Content? How do you avoid FOUC?
- Explain what ARIA and screenreaders are, and how to make a website accessible.
- Explain some of the pros and cons for CSS animations versus JavaScript animations.
- What does CORS stand for and what issue does it address?
- How did you handle a disagreement with your boss or your collaborator?
- What resources do you use to learn about the latest in front end development and design?
- What skills are needed to be a good front-end developer?
- What role do you see yourself in?
- Explain the difference between cookies, session storage, and local storage?
- Can you explain what happens when you enter a URL into the browser?
- Describe the difference between SSR and CSR. Discuss the pros and cons.
- Are you familiar with static rendering?
- Rehydration?
- What does a
doctype do? - How do you serve a page with content in multiple languages?
- What kind of things must you be wary of when designing or developing for multilingual sites?
- What are
data- attributes good for? - Consider HTML5 as an open web platform. What are the building blocks of HTML5?
- Describe the difference between a
cookie, sessionStorage and localStorage. - Describe the difference between
<script>, <script async> and <script defer>. - Why is it generally a good idea to position CSS
<link>s between <head></head> and JS <script>s just before </body>? Do you know any exceptions? - What is progressive rendering?
- Why you would use a
srcset attribute in an image tag? Explain the process the browser uses when evaluating the content of this attribute. - Have you used different HTML templating languages before?
- What is the difference between
canvas and svg? - What are empty elements in HTML ?
- What is CSS selector specificity and how does it work?
- What’s the difference between “resetting” and “normalizing” CSS? Which would you choose, and why?
- Describe Floats and how they work.
- Describe z-index and how stacking context is formed.
- Describe BFC (Block Formatting Context) and how it works.
- What are the various clearing techniques and which is appropriate for what context?
- How would you approach fixing browser-specific styling issues?
- How do you serve your pages for feature-constrained browsers?
- What techniques/processes do you use?
- What are the different ways to visually hide content (and make it available only for screen readers)?
- Have you ever used a grid system, and if so, what do you prefer?
- Have you used or implemented media queries or mobile specific layouts/CSS?
- Are you familiar with styling SVG?
- Can you give an example of an
@media property other than screen? - What are some of the “gotchas” for writing efficient CSS?
- What are the advantages/disadvantages of using CSS preprocessors?
- Describe what you like and dislike about the CSS preprocessors you have used.
- How would you implement a web design comp that uses non-standard fonts?
- Explain how a browser determines what elements match a CSS selector.
- Describe pseudo-elements and discuss what they are used for.
- Explain your understanding of the box model and how you would tell the browser in CSS to render your layout in different box models.
- What does
* { box-sizing: border-box; } do? What are its advantages? - What is the CSS
display property and can you give a few examples of its use? - What’s the difference between inline and inline-block?
- What’s the difference between the “nth-of-type()” and “nth-child()” selectors?
- What’s the difference between a relative, fixed, absolute and statically positioned element?
- What existing CSS frameworks have you used locally, or in production? How would you change/improve them?
- Have you used CSS Grid?
- Can you explain the difference between coding a web site to be responsive versus using a mobile-first strategy?
- Have you ever worked with retina graphics? If so, when and what techniques did you use?
- Is there any reason you’d want to use
translate() instead of absolute positioning, or vice-versa? And why? - How is clearfix css property useful?
- Can you explain the difference between px, em and rem as they relate to font sizing?
- Can you give an example of a pseudo class? Can you provide an example use case for a pseudo class?
- What is the difference between a block level element and an inline element. Can you provide examples of each type of element?
- What is the difference between CSS Grid and Flexbox? When would you use one over the other?
- What is the difference between fixed, fluid and responsive layouts?
- Explain event delegation.
- Explain how
this works in JavaScript.- Can you give an example of one of the ways that working with
this has changed in ES6?
- Explain how prototypal inheritance works.
- What’s the difference between a variable that is:
null, undefined or undeclared?- How would you go about checking for any of these states?
- What is a closure, and how/why would you use one?
- What language constructions do you use for iterating over object properties and array items?
- Can you describe the main difference between the
Array.forEach() loop and Array.map() methods and why you would pick one versus the other? - What’s a typical use case for anonymous functions?
- What’s the difference between host objects and native objects?
- Explain the difference between:
function Person(){}, var person = Person(), and var person = new Person()? - Explain the differences on the usage of
foo between function foo() {} and var foo = function() {} - Can you explain what
Function.call and Function.apply do? What’s the notable difference between the two? - Explain
Function.prototype.bind. - What’s the difference between feature detection, feature inference, and using the UA string?
- Explain “hoisting”.
- What is type coercion? What are common pitfalls of relying on type coercion in JavaScript code?
- Describe event bubbling.
- Describe event capturing.
- What’s the difference between an “attribute” and a “property”?
- What are the pros and cons of extending built-in JavaScript objects?
- What is the difference between
== and ===? - Explain the same-origin policy with regards to JavaScript.
- Why is it called a Ternary operator, what does the word “Ternary” indicate?
- What is strict mode? What are some of the advantages/disadvantages of using it?
- What are some of the advantages/disadvantages of writing JavaScript code in a language that compiles to JavaScript?
- What tools and techniques do you use debugging JavaScript code?
- Explain the difference between mutable and immutable objects.
- What is an example of an immutable object in JavaScript?
- What are the pros and cons of immutability?
- How can you achieve immutability in your own code?
- Explain the difference between synchronous and asynchronous functions.
- What is event loop?
- What is the difference between call stack and task queue?
- What are the differences between variables created using
let, var or const? - What are the differences between ES6 class and ES5 function constructors?
- Can you offer a use case for the new arrow
=> function syntax? How does this new syntax differ from other functions? - What advantage is there for using the arrow syntax for a method in a constructor?
- What is the definition of a higher-order function?
- Can you give an example for destructuring an object or an array?
- Can you give an example of generating a string with ES6 Template Literals?
- Can you give an example of a curry function and why this syntax offers an advantage?
- What are the benefits of using
spread syntax and how is it different from rest syntax? - How can you share code between files?
- Why you might want to create static class members?
- What is the difference between
while and do-while loops in JavaScript? - What is a promise? Where and how would you use promise?
- Discuss how you might use Object Oriented Programming principles when coding with JavaScript.
duplicate([1,2,3,4,5]);
- Create a for loop that iterates up to
100 while outputting “fizz” at multiples of 3, “buzz” at multiples of 5 and “fizzbuzz” at multiples of 3 and 5 - What will be returned by each of these?
console.log("hello" || "world")
console.log("foo" && "bar")
- Write an immediately invoked function expression (IIFE)
- What are some advantages/disadvantages to testing your code?
- What tools would you use to test your code’s functionality?
- What is the difference between a unit test and a functional/integration test?
- What is the purpose of a code style linting tool?
- What are some of the testing best practices?
- What tools would you use to find a performance bug in your code?
- What are some ways you may improve your website’s scrolling performance?
- Explain the difference between layout, painting and compositing.
- Traditionally, why has it been better to serve site assets from multiple domains?
- Do your best to describe the process from the time you type in a website’s URL to it finishing loading on your screen.
- What are the differences between Long-Polling, Websockets and Server-Sent Events?
- Explain the following request and response headers:
- Diff. between Expires, Date, Age and If-Modified-…
- Do Not Track
- Cache-Control
- Transfer-Encoding
- ETag
- X-Frame-Options
- What are HTTP methods? List all HTTP methods that you know, and explain them.
- What is domain pre-fetching and how does it help with performance?
- What is a CDN and what is the benefit of using one?
- What’s a cool project that you’ve recently worked on?
- What are some things you like about the developer tools you use?
- Who inspires you in the front-end community?
- Do you have any pet projects? What kind?
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