You've reached the one-hour code challenge stage. At this stage, be prepared to write production-grade code with full optimization for performance.

Don't be fooled by the engineer's relaxed appearance, which was the mistake I made. I was under the impression that the engineer would be happy enough to see fully working code. Once I finished the code, I wasted a good amount of time (10-15 minutes) chatting with him, time which I could have spent on refactoring and optimizing the code. In the end, you are mainly scored on your code alone.

I did complete the challenge in time and had a fully working solution; it's just not refactored to his satisfaction. I wish he had made his expectations clear from the beginning.

The book they suggested you read isn't much of a help unless you're a beginner JS developer. Don't waste too much time on that.

Some interesting projects on GitHub also didn't help. They were too complex and irrelevant for the actual simple code challenge. They may be useful for the final stage, but who knows?

Mostly questions about promises and related topics.