It was one of the least organized processes I have ever taken part in. A recruiter found me on GitHub because of my Python contributions and scheduled an interview with an engineer. She told me the interview would be on backend concepts in Python (no LeetCode questions or anything like that); I hadn't received any further information to prepare for the interview.

However, when the interview started, the interviewer wanted to cover a lot of computer science fundamentals I'd never seen in an industry interview before (such as Operating Systems – and the team had nothing to do with OS, but with web development – and math). If I had known the topics of the interview beforehand, I would have studied them, but I had no clue. (And, by the way, the team didn't work with Python but with Go).

There were no questions on things that I believe would have been more useful for a software development team (such as software architecture or databases) or "general industry" questions (such as LeetCode). I thought it was a terrible experience.

What is the difference between a mutex and a semaphore?

In math, what is idempotency?