I applied through an online job posting.
I was then contacting 2 weeks later by the Amazon recruitment team who arranged the interviews.
The first stage was a 45 minute phone interview was with a member of the department I applied too, the interviewer was very friendly, and followed the Leadership principles style of questions.
After this stage I was told 2 days later that I made it to the 2nd stage of interviews.
The second stage was a 45 minute phone interview with the hiring manager, she followed the same principles questioning.
I was successful with this stage and arranged a time for the final stage in person interviews.
The final stage was a 3.5 hour interview with 3 members of the team and an 'Amazon Bar raiser'. I was given a break after the first two interviews.
Each interviewer asked 2-3 Leadership principle questions, the interviews lasting 40-45 minutes each. They left enough time at the end for me to ask questions. They requested for the answers to be in a STAR format, they dived deep into the questions and had lots of emphasis on the 'Results' of my example.
Although the questioning is very structured all of the interviewers were very friendly, gave me a chance to ask lots of questions, and were open about the role and life at Amazon.
My advice would be to have 1-2 examples for each principle, follow the STAR answering technique, practice some questions that they may ask, research each interviewer so you know what they may focus on, and have at least 3-4 questions for each of them. Also it's really helpful to bring in notes and review between interviews.
I researched Glassdoor interviews, articles on the Principles by Jesus Gil Hernande, and Gayle Gallagher who published an article on 'How to maximise your chances of getting a job at Amazon'.
The Amazon interview process can be long and difficult, but it's only as difficult as you make it, if you do your research into the principles, and have experience and examples of using them, then you can be prepared for anything they may throw at you.