What is this?
Many front end interviews are highly-focused on domain knowledge and applying them to real-world scenarios. You might find that grinding LeetCode is not all you need when it comes to interviewing for a front end position, but that's a good thing! Front end interviews tend to test concepts that are more practical and relevant to real world front end development. But that doesn't mean that you don't have to be familiar with basic data structures and algorithmic concepts - there's just less emphasis on them and you are probably going to get easier algorithmic questions.
While there are some existing resources to help front end developers in preparing for interviews, they aren't as abundant as materials for a general software engineer interview. Among the existing resources, the most helpful question bank would probably be Front-end Developer Interview Questions. Unfortunately, there aren't many complete and satisfactory answers to these questions readily available online. This handbook answers these trivia-style questions along with information and guidance for other front end interview formats.
However, I've recently used and reviewed GreatFrontEnd, a platform calling itself "the LeetCode for Front End interviews". It contains Front End interview questions and answers written by ex-FAANG Senior Engineers and have both questions and answers for various formats: coding and trivia-style front end questions. I found it to be very useful and I highly recommend checking it out!
General tips for front end interviews
Regardless of which type of format you are given, one thing stays true - you need to be extremely strong in your front end fundamentals and constantly display mastery of them to your interviewer.
Be extremely familiar with the following concepts:
- CSS: Specificity, Box model, Layout, Positioning
thiskeyword, Prototypes, closures, Async-style code, Promises, Timers (
- HTML: Event delegation (it was useful in almost every interview), DOM traversal, DOM manipulation, Form validation and submission
- Vanilla JS, or jQuery at the very least. Not all interviews allow you to use React as they want to see mastery of the fundamentals
Look out for interview questions by companies on Glassdoor. Front end questions are not as abundant but some still can be found. Many companies use similar questions.
Front end interview formats
Unlike Software Engineering interviews, the formats for front end interviews are less known and not standardized across the industry. We have made the effort to search the Internet for front end interview questions asked by the popular companies and there are some questions which appear very often. In general, you should be familiar with the following questions and formats:
Short questions which test your knowledge and have clear non-subjective answers. These are usually asked by recruiters because the accuracy of the answers can be verified even by non-technical people. Here are some examples:
- What is a closure?
- What is the difference between a promise and a callback?
- Explain the
- What is the CSS box model?
- Various CSS
positionproperties and its differences.
- Implement DOM APIs:
- Implement Promise/Promise-related APIs:
User interface coding
- Autocomplete (very popular)
- Photo gallery
- Image carousel
- Tooltip component
- Star rating widget
- Build tic-tac-toe
- Build a chess board with movable pieces
Describe and discuss how you would build a UI component/app/game and its architecture. This is the front end version of system design questions. E.g. Describe how you would build the Emoji autocomplete feature in a chat app, what APIs it would have, what components there are to the feature, how to ensure it has good performance, UX, etc.
- Design an image carousel component.
- Design an email client application.
Company interview formats
Through extensive research, here are the different type of formats companies ask during the technical rounds of front end interviews. If you're interviewing for front end engineering roles at certain companies, prepare accordingly!
Legend: ✅: Asked, ❌: Not asked, ⚠️: No data