Well organised, quite lengthy and unfortunately way too many competency questions with quite an unhealthy emphasis on their "leadership principles".
I applied online to the BDM role, and the next day I got an email from a recruiter (#1) telling me that they've reviewed my CV and are interested in starting the interview process, which will be:
1- Telephone Interview (Competency Based) 45 minutes
2- In-house Interviews (Competency Based) ----- (NOTE the plural "s"!)
After sharing availability times, the telephone interview was confirmed with a category manager (10 days after first email I received). The recruiter explained to me in full detail what it would include: going through my CV and experience, a role play (based on attached file) and 2 competency questions that need to be answered in a BAR/STAR format, and would be assessed directly against Amazon’s Leadership Principles (which you can find on their website).
2 days later I got an email from another recruiter (#2) and she told me that I'd been successful (I'd felt that myself). She asked for availability for the last round of interviews and it was schedules for 10 days later (again :-/). She then sent the schedule of who I'd be meeting that day, with a brief interview guide attached.
There were 4 (yes that's right, 4!) 45 minute session with various managers. The first wasn't a interview but a meeting with a quite junior manager (and another colleague) who were ambassadors telling me about amazon and also asking about my motivations and such. Note that this was already asked by the more senior manager on the phone and would be asked another 2 times later. The next session (first 1:1) was with another category manager and he asked me some questions about 2 principles. The next session (2nd 1:1) was with the UK RVR Head (and ultimate hiring manager) and he also asked me questions about 2 other principles - didn't do so well on those (sometimes you just can't come up with a good example even with prior practice). The last one after a lunch break (3rd 1:1) asked me about 1 other principle.
As you can imagine, talking so much will really deplete your energy (and give you a very dry mouth!) so try to drink a lot. You will naturally be at your weakest on the 3rd one, before the break - a suggestion for Amazon would be that they not put the ultimate decision maker in that slot...
The people were all nice and helpful, but I do have to agree with the many other people here on Glassdoor that their "obsession" with their "leadership principles" is not an attractive thing - wanting specific answers, for all those different competencies, especially since we all know that every person has different strengths and weaknesses, is definitely a weird way to hire people, esp. in this day and age where most companies (big and small) look more for 'fit' than anything else.
I also noticed a "big company mentality" where quite a few of the people I spoke to used the exact same phrase: "Amazon is/We are quite weird" "they don't care what you do as long as you deliver" etc. - as cool as they like to present themselves, it still makes me think that like nearly all big organisations, conformity is mandatory if you want to be there (and hence the aforementioned obsession in hiring and operations with a set of principles).