There is a behavioral and technical parts of the interview. In total, it lasts about 2 to 2.5 hours. For the technical portion, be prepared to work out physics/dynamics problems.
I applied through university. I interviewed at Amazon Lab126
Interview
Applied online and received an email about 2 weeks later. They assigned you two 45 min interviews back to back, over video chat. 50% of it were behavior questions and the other 50% were technical questions for each interview.
I applied through an employee referral. The process took 1 day. I interviewed at Amazon Lab126 (Sunnyvale, CA) in May 2019
Interview
Multiple rounds, focused mainly on past experience and STAR questions. Some how would you do this type questions. Interviewers were part of the team that I would hire into. Easy to talk to.