It was a full day interview process. The tour of the campus is very impressive, and then a demonstration of the software helps to show what exactly you are working towards. This is enough to make anyone excited about working for them. (The free lunch they provide made by culinary experts helps as well). It takes a bit, but applicants should work to get past the bells and whistles of the place, and take the time to ask questions of the people you meet with who actually hold the position you are applying for. They will give you good feedback on what you will be doing.
The interview itself consisted of an informal 10 min presentation, 2 half hour one on one interviews, a case study with another individual, and then a math, english and programming written test.
It is a good process as you have many opportunities to truly sell yourself. Also, though you are meeting with numerous applicants at the same time you don't feel as if you are in direct competition with them because they are expanding so quickly. If you are qualified you will get an offer.