The initial phone interview with a Booz recruiter lasted about 10 minutes where I was asked very general questions about what I do at my current job and expected salary. My face-to-face interview was a couple of weeks later where I met with 5 or 6 individuals for about 30 minutes each lasting about 3 hours. The interview wasn't too difficult. However, be prepared to work around the interviewers schedules. One individual was located off-site and had to interview by phone, another was caught up in a meeting and came late, and there was a period of about 20 minutes where I was left by myself waiting for the next interviewer to show up. Everyone was very nice and honest though and answered all questions.