After the HR call, I had two phone screen interviews, then an on-site interview.

The phone screen interview was pretty straightforward, with some coding exercises and questions about Linux knowledge.

For the on-site interview, I did not do very well in the first round of coding. For the rest, I would say I did okay, but it looked like we disagreed with each other in some areas. Different use cases have different system design solutions. During the on-site interview, some interviewers did not try to put themselves in my shoes before challenging my solution; they might have just wanted a fixed answer instead of an explanation of some tech fundamentals.

For the candidate, I would suggest that if you believe in a design, then insist on your solution even if they challenge you (of course, you need to explain why based on your use case and trade-offs).

The interview was not difficult, but keeping an open mind is very important, for both the candidate and the interviewer.

Can't say too much, algos about array/string/tree and Big-O.