Amazon Operations interview questions

I approached the Amazon table at the Supply Chain Management career fair at my university. After talking to one lady I was motioned over to talk to the person in charge, I handed in my resume and schedule an on-campus interview for the following day. The interview was very relaxed and I felt quite comfortable speaking with the Amazon rep. They asked typical interview questions and asked 1 moderately simple math-based operations question. I actually forgot a step when I went over my answer but the interviewer nicely pointed it out and let me finish the problem again. I felt great after the interview but was not contacted for another month afterwards. A phone interview was set up for the following week that included a math-based operations question that needed to be completed before the interview. A couple days after the phone interview I was contacted very warmly by an HR rep with additional details. Overall it was a great interview process, definitely do research and be prepared for some in-depth behavior based questions.