Amazon Software Development Engineer-II interview questions

Hiring process kicked off with programming exercise with on-site 4 level of interviews. All interviews were based on problem solving, algo and DS. They are looking for people having great skills in problem solving thus be prepared to be grilled on that aspect. One of the interview would be on Object Oriented designing thus be ready to spill out your OOAD concepts. Be ready to write code on white board.

I have given the interview thrice in 2 years. Following are the outcomes: 1st time: I was in delhi. I have given 2 rounds of telephonic interviews for which I had to email my code for the problems discussed over phone. Then I was called to hyderabad where I gave 5 rounds. Every round went very good. I waited for the reply but even after a week, I got none. Then I contacted HR and she emailed me that they are not hiring me. I asked for the reason and she replied that the problem solving was slow. 2nd time: This time, I was in bangalore and I got a call for interview at World Trade Center, Malleshwaram. I only had one round In which I was asked a very simple question which anyone can answer. Then they told me to wait for some time and finally after 2 hours, told me to leave. 3rd time: This time too, I was in bangalore and I got a call from same office (World trade center). They asked me to give a written test in which code for 2 problems out of 3 had to be written. The problems were easy and I have solved them earlier, and I wrote everything including complexity analysis, code, psuedocode and comments in the code etc. But I got a reject. The HR told me that my answers were not at par from their standard. Overall, In each interview, I was rejected without any reason. I felt cheated in the interviews in bangalore because they made the decision to reject based upon the correct answers I have given, and for which I have put my time and effort in preparation. I dont know why they have openings every week. It is like every week they call some people, and reject them even if they answer correctly. I think it is a abuse of software engineers who are sincerely willing to work with amazon by those, who are working at amazon and interview candidates for self gratification. I would say that even if you give all correct answers and perform very well in the interviews, your chances of getting into amazon is still 50-50.