Amazon Senior Developer interview questions

I believe I answered the question correctly, honestly I am not sure why I got rejected, didnt get any feedback. I got asked a well known leetcode medium level question and gave a proper answer including the runtime. Sometimes it was difficult to understand the interviewer's English, may be he didnt actually understand what I actually said, not sure really... Still trying to figure out... what actually went wrong.

Total of 7 interviews lasting 7+ hours. Two 1 hour interviews. Hackerrank/leetcode style programming tasks followed by behavioral questions. The final loop of 5 interviews over 2 days. All interviews were remote. Some things I learned. The advice to have a couple of stories per leadership principle was useless. All behavioral questions were of "tell me about the time when you did X/reacted to Y/Z happened". There was no way to prepare for these kinds of questions. I honestly feel that I flopped on all of them. After all programming tasks, I was asked to calculate time and space complexity. Nobody I know does that in practice but it is a must for interviews.