I had a 30 minute on-campus interview followed by an all day on-site interview. The 30 minute interview was a pretty short get to know you sort of thing. I had to read Ruby code and explain what it did. I had never read Ruby before, but there were some printed out pages of the api as a reference. The on-site interview was longer. It started with a dinner the evening before. The day of there were three main sections, code reading, technical writing, and code writing. Each segment lasted roughly an hour. After those three interviews were completed, everyone interviewing participated in a team interview and worked together to complete a challenge. I have interviewed at Microsoft, SpaceX, HP, Google, TI, etc. I've hit all of the big name companies. I never was introduced to the atmosphere of the company though. This place is really cool. Throughout the interview process I knew that I didn't want to continue my job search.