A few days ago, I had my first whiteboard interview for which I had to practice my JavaScript skills using various coding challenges found online. Below I want to share the coding challenge websites that stood out to me and helped me over time in the process of learning programming:

1. Codewars

This is my personal favorite, since they have various difficulties, from beginner to the very advanced and they employ a ranking system similar to the one encountered in the Japanese martial arts.

2. HackerRank

HackerRank was actually recommended to me by the company I was interviewing for. They have curated challenges from many companies.

3. Edabit

If you are an absolute beginner I strongly recommend starting with this one since they have very easy problems.

4. LeetCode

LeetCode features more advanced challenges and contests. If you have some experience, this one is for you.

5. freeCodeCamp

freeCodeCamp has also a collection of hundreds of challenges that you can practice your skills on.

6. Exercism

Exercism gets also a mention since they provide you with mentor support to provide feedback to your challenge solutions.