It was a standard initial phone screen by a recruiter that took about an hour. After the first phone screen, the director of my department called and interviewed me for about an hour. Up until this point, none of the questions asked were really technical, mostly they were about my past experience. After the second phone interview, I was invited on site for a final interview. In the span of about 3 hours, I interviewed with 3 different groups each containing 1-3 people. Each group asked a variety of technical questions pertaining to their areas of focus as well as the standard interview questions about my experience. At the end of it all, even if I didn't receive an offer, everyone I dealt with was very professional and respectful. Oddly enough, everyone I interviewed was so laid back about everything that it was one of the more relaxed interviews I've had without lacking any of the substance from a typical uptight interview.