Received an employee referral, through an informal interview with a director. Had my first phone interview sometime last November, which consisted of a behavioral interview. Then a few weeks later I had a case interview. This was the "ED" case that was mentioned by others. Very easy. I was then contacted and asked to come into their office in Chicago for the final round of interviews. This consisted of a group/panel interview. and then 3, 1:1 45 minute interviews. This final round of interviews began at 7:30 in the morning. All of the interviewers were young, which was nice, yet they all seemed very nonchalant when it came to the interviews, giving off the impression that you already received the job offer and just wanted to be "buddy buddy" with you. I was not given an offer, and amazingly, when I asked for feedback from the recruiter, I was told that I seemed too nervous during the interviews, and I didn't have enough job experience. Makes a lot of sense, why would they drag me this far into the interview process knowing of my job experience. Felt like I got screwed.
Be careful as to say exactly what you think they want to hear, and not what you want to instinctively say.