Got the interview through university recruiting. The main human resources person called me up for a phone interview first. Then they called me back to tell me they'd like me to come up to their site for an interview. They flew me out and got interviewed with around nine other students. First got a presentation of what the company was. Then was given a written assessment (not too technical). Then went on a tour of the facility. Given lunch. Then did one on one interviews with around six of seven people. The interviews consisted of pretty general questions that all interviewers ask. Only one asked me to optimize an actual product. Interview was only difficult in that I was set up against graduate students and students who already had pretty good prior internships (I'm assuming they learned more on their jobs than I did).