Amazon Non Software Development Engineer interview questions

I had two telephonic interviews for about 45 mins each. The focus of the interviews was data structures, algorithms, oo design concepts and basic coding. Once I cleared the telephonic interviews, I was called in for an onsite interview which again focused on the same areas but little more in depth. I had 4 45 min 1:1 technical interviews. I had to work on one problem in each of the rounds. Problems focused on random numbers, trees and problem solving. I had 1 hour of lunch interview with the hiring manager. He explained about the group, work culture. He asked me to talk about my research and asked one technical question at the end. I liked the people. Casual work culture.