Front-End Dev Interview Questions

Based on my experiences searching for a job in Toronto 2014.

Interview formats:

• Screening phone call
• Non-formal chat about position
• Formal interview that covers non-technical and technical questions
• Interview Test
• Technical Interview

HR questions

• Tell me a little bit about yourself.
• What have you learned this week?
• What have you been up to since X?
• What side projects have you been working on?
• How do you indulge yourself in the industry? How do you stay current?
• Why did you take a web development bootcamp after a Comp Sci Degree?
• What about CompanyXYZ interests you?
• What type of company do you want to work for?
• Why do you think you'd be a good fit?
• What is your biggest character strength and weakness?
• If you could work for any company, which would it be and why?
• Where do you want to be in 5 years?
• What music do you listen to? - They replied with yeah we play X here in the office.

Technical questions

HTML

• What is a doctype?
• Can you name some HTML5 elements?
• What are the new media-related elements in HTML5?
• Have you worked with Canvas?
• What are SVGs?
• What are different types of storage in HTML5?
• Are you familiar with Jade or Haml?

CSS

• What is a rem unit? When do you use them?
• What is an example of a pseudo element?
• What are vendor prefixes?
• Do you use bootstrap?
• Do you have any experience with CSS preprocessors? Have you used LESS or Sass?
• How many different ways can you apply styling to a webpage?
• What does the CSS Child Selector do?
• Explain the properties of Float in CSS?
• Using animations what CSS property do you use to increase/decrease the size of an element?
• How do you guarantee a section of CSS will override any other reference?

Responsive Design

• What is Responsive Design?
• Have you used break points?
• What are a few different ways you could implement Responsive Design?
• What is Mobile first design?
• How familiar are you with adaptive design and development?

JavaScript

• Have you used any testing on your code?
• Are global variables good or bad?
• Have you used any other JavaScript Libraries?
• What is the difference between == and === ?
• Have you used CoffeeScript?
• Do you lint your code?
• Which linters do you regularly use?
• What is event binding?
• How do you prevent event bubbling?
• How do you trigger multiple events on click?
• What are namespaces? Give an example.
• When you write your JavaScript, do you choose functional programming or object oriented?
• Describe how you would make a JavaScript object. How would you call a function inside of it that accesses a property of that object?
• When would you use a JavaScript animation over CSS3 Animations? Explain why.
• You have a button outside of a form, describe how you would use JavaScript and jQuery to collect data from the form after clicking on the button and what would you do with the data?
• What is use 'strict'?
• How would you design a large scale project with JavaScript?
• Explain what happens when you make an AJAX request?
• What happens when you use var?
• What is a Callback function?
• What is a Promise?
• What is a Closure?
• What is a Prototype? Give an example.
• What is Prototype Chaining?
• What does the bind() function do? What does the call() function do?
• What is Inheritance in JavaScript? Give an example.
• How would you assign Child Specific Objects?
• What is require in JavaScript? How could you use it to reduce load time to a webpage?

Computer science questions

Using any programming language and being syntactically correct as possible, on paper:

• Write out a function that solves the Fibonacci sequence.
  • Write a function that solves the Fibonacci sequence a different way.
  • In big O notation compare and explain the complexity of both functions.
• Write out a function that computes a Factorial given a non-negative integer number.
  • Write out the function a different way.
  • In big O notation compare and explain the complexity of both functions.
• Given an Array of Integers, write a function that computes the sum of the two largest numbers.
• Fizz-Buzz: Write a function that iterates through the numbers 1 - 100 and if the number is divisible by 3 print "fizz", if its divisible by 5 print "buzz", if its divisible by both then print "fizz"

Client scenarios

• If a client has called you and said that the web page is loading slow, what steps would you ask the client to take to diagnose the problem?
• If you have just finished a project for a client and the client says the web page needs to have a video feature incorporated, assuming the implementation takes 1 extra week to implement, how would you reply to the client?
• While you are implementing the new change you discover a bug that pushes your time line back by 3 days, how would you reply to the client?

General questions

• How would you rate your skills 1 - 10 of the following:
  • HTML
  • CSS
  • JavaScript
  • jQuery
  • PHP
  • Wordpress
• When you start a new project, what is your development approach?
• What's your typical workflow like?
• What type of projects would you prefer to work on, JavaScript or HTML & CSS?
• What is your preferred development environment?
• What do you do when you find a bug?
• Do you blog?
• What blogs do you follow to stay up to date?
• Who do you follow on twitter?
• Who is the best developer that you've ever worked with and why?
• Do you speak at conferences or lead workshops? Have you done public speaking in the sector?
• Have you contributed to any open source projects?
• Have you participated in a hackathon?
• How many different ways can you center text vertically and horizontally on a page?
• How can you make a div the height of the page?
• Name as many ways as possible to make text not display on your page.
• How do you optimize a website's assets?
• Name three ways to reduce page load time?
• How would you rate one of your latest projects out of 10? What would you change about it?
• Do you use Photoshop? Can you slice a PSD and get assets out of it?
• Are you familiar with version control? Do you use Git, Subversion or Mercurial?
• Have you worked with a CMS?
• What browsers do you typically test in and support?
• How would you test if you could use a microphone inside the browser on a mobile device?
• Are you familiar with Cross-browser compatibility testing? Have you used it on any projects?
• What is a polyfill?
• What do you use as your primary text editor?
• Do you use Github and/or Bitbucket?
• What is your testing workflow?
• Have you worked with a team before?
• Are you familiar with Agile methodologies?
• What is Test-Driven Development?
• Do you think you're a fast learner? If so, why?
• What was the most difficult project you worked on and why?

How to prepare for an interview?

• Research the company
  • Why do you want to work for them?
• Research who you are interviewing with
• Minify your live projects and personal website
  • Be prepared to have the interviewer pull up your website and project and view source.
  • If it is minified then they might start a conversation about what task runner you used to minify it.
  • If it is not minified then they may pick apart your code and poke around.
• Review your projects' code.
• Review your resume
  • Anything listed on your resume is fair game. If you listed SQL as a skill then be prepared to answer questions about SQL. Only attribute skills you are confident in.
• Read the job posting.
  • If they list "nice to haves" technologies that you've never heard of, then spend some time learning what they are.
  • Brush up on skills that they're looking for.
    • If they're looking for a candidate for an AngularJS project, maybe spend a few nights building an app with it.
• Familiarize yourself with some of the latest web technologies
  • Frameworks
    • Angular
    • Backbone
    • Ember
    • ReactJS
    • Meteor
    • Bootstrap
  • Libraries
    • Lo-Dash
    • Modernizr
    • Underscore
    • Marionette
    • WebGL
    • threeJS
    • D3
    • Processing
  • Task Runners
    • Grunt
    • Gulp
  • Testing Frameworks
    • Jasmine
    • Mocha
    • QUnit
  • Test Runner
    • Karma
  • Tools
    • NPM
    • Bower
    • RequireJS
  • Preprocessors
    • HTML
      • Jade
      • Haml
    • CSS
      • Sass
      • Less
      • Stylus
    • JavaScript
      • Coffeescript
  • Canvas
  • NodeJS
  • MEAN stack

What to ask at the interview?

• What type of work do you usually do? What are you working on right now?
• Whats your favorite project at the moment, why?
• Do you generally do product work or advertisements?
• Do you build static websites or CMS? .com or apps?
• What type of clients do you generally deal with?
• What is a typical day in the life as that role?
• What would my responsibilities be?
• What is your stack?
• How big is your development team?
• What are the tech backgrounds of your developers?
• What front-end technologies do you use?
• What is the culture like at XYZ? What is your company culture?
• Do you guys eat lunch together?
• Do you have social events?
• Does the company do hackathons?
• Are you supportive of developers attending conferences?
• Your company has a foosball table, but do you actually use it?
• Where is the beer fridge / scotch cabinet?