I spoke with a college recruiter and was asked to draw a block diagram of one of my projects and explain how it works. I was encouraged to apply for the internship and was contacted in 3 weeks for an in person interview. The interview took about an hour, 30 minutes with one person and 30 minutes with another. The first 30 minute interview was mostly technical. The second 30 minute interview was more casual and behavioral. Both were conducted by engineers at amazon lab126. Some technical questions were tricky but overall average interview difficulty.