Prepare Coding Interview — JavaScript

how to Ace your JavaScript Coding Interview

Steven(Liang) Chen
3 min readJan 29, 2022

This blog will focus on two kinds of JavaScript algorithms and vanilla JavaScript rounds. I will share my experience with how I prepare it.

1. Coding Style:

Before we go further I would like to mention the JavaScript Style guide. This plays an important part in your coding interview. Below is the most popular javascript style guide adopted by many big companies.

2. Prepare Algorithm Round:

2.1 Unit Test:

The best platform is definitely LeetCode. But I would like to recommend you to do the LeetCode question locally with writing unit tests for each one.

Because there are opportunities that interviewers will ask you to write unit tests during the interview. Besides, writing unit tests is a good practice.

If you find some data structures are missing and you need to implement them by yourself you can always find the example in the following repositories.

2.2 Repeat! Repeat! Repeat!

It is very common that you cannot resolve the question you have resolved previously. Given my experience, the best practice in this situation is to do the question around 4 or 5 times.

Let’s take Two-Sum as an example. For every single question, you should follow the Ebbinghaus memory curve. After resolving the question the first time do that question again on the following day, in the next week, and in a month's time.

There is no shortcut to master the algorithm interview. Just keep practicing and repeating.

2.3 How to choose Algorithm questions

There is a feature in LeetCode premium you can choose the question set under a particular company. Normally these groups of questions cover all the algorithm categories.

3. Prepare Vanilla JS Coding Challenge:

Some companies prefer vanilla javascript challenges rather than algorithm questions. In this case, I would like to recommend this online course to practice your vanilla js(without any framework).

This course has an associated GitHub repository with solutions. You can resolve the challenge by yourself and then check the solution.

If you find the 30 questions above are not enough or you just want to do more challenges you can check this GitHub repository as well.


Hope this blog can save you some time while preparing for your next coding interview and secure a better opportunity. Apart from the above resources I highly recommend you to do some mock interviews online or with your friends.

This blog doesn’t cover how to do take-home assignments as I find that might be a big topic worth writing a separate blog. I will write another one for it. Thanks for reading hope you like it.