Amazon Senior Project Manager interview questions

First round: I had a couple of 30min phone interviews with product managers. I have been asked general questions such as "why Amazon" and "Why product management". In the first interview I had a mini-case question and in the second one I was given a market sizing question. Final round: I was invited to Seattle for a final round interview. I had 4 interview with different people, about 45 minutes each. I was asked lots of fit/personal experience questions: "tell me about a time you had to explain a technical issue to senior management", "what is your most significant career achievement", etc. Also some Amazon-specific questions: "what is your favorite Amazon product and why", "why Amazon" etc. Each interviewer also gave me at least one mini case, e.g. "how would you design an online billing system", "how would you change an Amazon webpage to increase sales".