I had two behavioral interviews that were focused on the 17 (ish) Amazon Leadership Principals. You must add specific data points to every answer you give, if you don't they will continue to push you for data in your answers.

Two (or was it three?) phone interviews, and an onsite day with six interviews. All interviews felt quite strange as they were behavioural questions, so we were just talking about my past experiences, and I never felt like I was asked a typical interview question. But that said, I felt like they knew quite a lot about me and my experiences by the end of it.