Amazon Sr Developer interview questions

Fairly typical sequence of events: recruiter chat, remote tech screen, in-person full-day interview. I interviewed with two teams and was told by the recruiter that other teams might also be interested in speaking with me. I left the interviews with a good feeling, but was told two days later that I would not receive an offer, and - most frustratingly - that I would not receive any feedback as to why I was turned down. So I have no idea in what ways I might be able to improve.

During the last 2 years, Amazon reached out to me from many different locations, such as Toronto, Vancouver, Seattle, Den Haag, etc. After phone screenings, I got invited to on-site interviews from 2 different offices, Toronto and Seattle. I got 3 of the 4 questions correct during the interview at Toronto. The question I failed was the bar-raiser and they left me 20 minutes to solve it, not enough time to code a complex question on white board. They decided not to make an offer and if I haven't asked, they were not even going to let me know. Months later I was invited to Seattle, but then it was redirected to Den Haag office in Netherlands (with my agreement). Then they asked to have another phone screening from Den Haag and as a result they cancelled the on-site interview, saying they do not want to proceed, although I answered their questions correctly. And lately, I got an on-site interview invitation from an Amazon recruiter in USA, whom I never talked to before. Long story's short: Recruiters do not read your emails correctly (or at all), and have no idea what they are doing. Whether you pass a technical interview or not completely depends on the mood and ego of your interviewer on that day. Because with enough years of experience, you already know if you actually passed a coding question or not. They are still trying to reach me from different offices, from time to time, but really, not a bit worth the trouble.