I was referred by a friend and got an interview request from the recruiting manager shortly after... The interview process was by far the most thorough I have ever been through. Granted, the whole process took about 6 weeks it still felt like a pretty fast process to me.
I had two screening interviews before going on to the final rounds. Screening interviews were both behavioral, with the interviewer asking several follow-up questions after my answers... If you've ever done a McKinsey behavioral interview - it is something like that. After each screen HR got back to me pretty quickly to let me know when and how the process would move forward.
For the final interview I was flown in to Seattle to meet with members of the team I would be working with as well as one person who is what they call a "bar raiser". I interviewed with 6 people in total and had lunch with another member of the team. Each interviewer asked behavioral questions as well as pointed case questions that were directly related to the job. The cases are not so much like consulting cases - they are more business cases but structuring your answers and approach will help make it easier for your interviewer to follow. I was surprised though that each interviewer had a case question so be prepared.
My interviewers were all polite, attentive and unbelievably professional. There was only one interviewer who kept yawning the whole time and didn't look as interested in conducting an interview or be in the same room with me. It threw me off my game a bit but other than him every other member of the interviewing team was stellar. I felt great after the interview knowing that they were really looking for the right person for the job and that if I did not move through it meant I was not a great fit. I was very pleased that it wasn't your run of the mill interview but 90% related to what I would be doing should they go ahead with me. Alas, I didn't get the job but with no hard feelings whatsoever! I got the call from my HR coordinator a day after the interview - so they are very fast with their decision.
All the best to all who read this and find it useful.