I had a phone interview first with a lead engineer on the project I'd be working on. He asked a lot about my background, the languages and methods I used, and just a few basic technical questions.
Within an hour I was asked to come in for an on-site interview, where the same person from the phone interview met with me, gave me a tour of the building, and led me to a room where I would be meeting with several other people separately. The whole interview was composed of meeting with 5 people, each for 30-45 minutes, with no breaks in between. Their questions were not very hard, but the constant stream of people entering the room as the previous person left for 3 hours felt very intense.