The interview process was pretty low-key. One group brought me in for an interview (flew me across the country, put me up in a nice hotel) and since I was already there, connected me with another group that might be interested. I had about interviewed with about 6 or 8 people in each group, 10-20 minutes each, and they didn't ask me super-specific technical questions to test my ability. They were much more interested in hearing me tell them what I did know and seeing if it was a personality match.