Went to the interview loop, speaking with 5 people (4 team members, one non-technical irrelevant to the team). A bunch of behavior questions. The technical question was just checking if I had done what they were trying to do.

They were very vage about what they wanted, so it was hard to show skills in that area. They were unclear if it was lens design, optomechanical, optical system, .... They hiring manager also asked illegal questions to figure out the candidates age, and they persisted until they obtained it. Shame on Amazon.