Amazon Software Developer interview questions

I applied online submitting my resume. The role was intended to be for fresh graduates from computing-related fields. The hiring manager contacted me in mail asking for the most desirable date and time to have phone interview. The phone interview lasted around 30 minutes. The interviewer was an engineer from Amazon Research Lab at Edinburgh asking me first the questions about my background, studies at the university I was then doing Master's course, and finally, questions regarding my skills in Java. The Java part was about collections, syntax and exceptions. It was heavily Java collections questions with problem, use case scenario and a question on how I would solve it, which data structure would chose and what the overall computing complexity would be as a result. I have not been successful in getting next round of the interview. The hiring manger contacted me in 3 days after phone interview letting me know that they made decision not to continue with my application.

Initial contact was made through a recruiting agency, not Amazon itself. There was a technical screening (90 minute coding problem, not solvable given the time constraints). Following this, was a trip to the Seattle campus for 4 hours of 1 on 1 interviews. I found the campus trip to be exhausting, and a little bit un personal. Each interview was about 45minutes of technical / leadership questions. There did not seem to be much time for interpersonal and workplace culture interaction.