3 rounds of interviewing.
First round was a behavioral interview with the Office Managing VP. Very standard behavioral questions.
Second was a technical interview over the phone. You just talk about the technical details of projects you've worked on.
Third and final round is an all day on site interview. There was a technical interview, a case study, and lunch with a peer.
In the case study, I had to come up with the optimal schedule of a programming conference given data such as how many rooms there are, capacity of each room, which teachers are teaching which classes, what types of attendees (architects, developers, dbas, etc) want to attend which classes, etc. Then you must present your solution and methodologies used to arrive there to a panel of executives.
Despite the fact that I did not receive an offer, I still came away with a very positive opinion of the company. They are very professional, responsive, and thorough in their interviews and communications.