Let me start by saying this was one of the more tedious interviews I've been to.
Step 1: Email from recruiter asking whether I'd be willing to relocate, when I could start, etc.
Step 2: Online questionnaire that included 3-4 recorded answers (situational questions and one open ended question), as well as a couple of logistical questions again (start date etc). There was also a tricky math problem too. **Take this step seriously, my friend got rejected from this step, so they definitely take the online screening seriously.**
Step 3: Onsite interview. This is probably one of the more boring, tedious, long winded interviews I've attended. Amazon pay for everything including flights, hotel, rental car, and meal reimbursements. The interview consists of 5, 45 minute interviews as well as a 15 minute facility tour. The interviews are a little intense and somewhat awkward at times. Each interviewer really has a different personality and this seemed to dictate how that particular session would go. 2 out of the 5 were very friendly and open conversations, 1 of them was a pair of people interviewing me and they kept asking situational questions and what I learned. 1 of the sessions, the amazon manager just straight up read off his question sheet with no personality himself and long periods of silence. The last interview was with a different manager who was very full of himself and I could tell from the beginning he'd be cocky especially in his accepting of my responses. Oh, and the math problem they give you as an example ok the welcome packet, practice that one because the interview math problem is similar.
Prepare for the onsite interview very thoroughly. Being such a long, tedious interview, they will definitely dig a little deeper than your initial response to a question.