I applied online, and the process took two weeks.

They invited me to a Slack channel where it was supposed to be a video interview. As it turned out, the hiring panel was busy, so they only asked questions over chat. Over chat, it is difficult to understand the sentiment behind the question. Later, I was asked to explain my code of Tree Of Space, where the interviewer asked me to optimize it. When I asked for a hint, they told me that no hint could be provided. When I couldn't optimize the code, he told me that the interview was over and that HR would update me, which basically meant I was rejected.

Optimize the code for Tree of Space.