Amazon Sr. Product Manager interview questions

Contacted by an Amazon recruiting coordinator who set up an initial phone screen with the hiring manager. The initial interview was two weeks after the first contact took about an hour. It was a combination of basic background and information about the position. This was followed by two additional phone interviews over the next couple of weeks with different people in the department. After making it through the phone interviews, I was scheduled for an all-day in-person interview. I met with 7 different people one by one, including a lunch with one person. I also met with a recruiter who told me she would be following up with me. Each of the people I talked with on the phone also interviewed me in person. Each person was cordial, but no nonsense. They never really tried to sell me on the job or the company. All seemed very smart and, in a couple of cases, kind of overbearing about it. But overall, very professional and capable people interviewed me. Why did I mark this down as a negative experience? Simply because they never contacted me afterwards to officially say no offer. No follow-up. Zero. I waited a couple of weeks, sent an email to the recruiter and the hiring manager and never heard back. When you go to all that effort to bring someone in (after 3 phone interviews) and then drop the ball when it comes time to closure, it's simply unprofessional and kind of sad.