Amazon was doing on campus interviews. Had one initial interview on a Wednesday. They then invited me back for two more interviews on Thursday. This should have been three however one of the interviewers wasn't able to make it so I ended up doing a fourth interview later over the phone. All interviews were very technical in nature. They asked one or two questions about my previous experience and then started asking about data structures, object oriented programming and algorithms. All interviews were about an hour long. I heard back from them about a week after the final interview.