The questions were exactly what the recruiter told me they may ask for example, which I did not expect! It was over zoom, so I did not have access to a whiteboard. It would be very helpful to write formulas on the board to reduce confusion. The reviewer was confused about something very trivial. His confusion stressed me out and distracted me from the main problem. So I did not do a good job. At the end of the interview, I learned more about the team and figured that I am not interested in what they do.

7 Interviews, didn't receive an offer after the final round. Time-consuming process, which includes multiple rounds of technical interviews (design, coding, behavior, etc.) and a 1-hour research talk. The team leader was unpleasant to interact with.