Initially I had a phone interview, and was told back that I would hear back in a week. Exactly a week later, I was asked to come in for a mini "superday" at the New York office with a couple of other candidates. There I had one on one interviews with a Partner, Director, and Manager. My first interview was with the partner and it was pretty laid back. He wants to see if you would be a good fit and if you could add value to the group. My interview with the director was the most specific and I was faced with a good amount of technical questions regarding the group I was interviewing for. Also there were a good amount of behavioral questions as well. My interview with the manager was similar with that of the director as I was again faced with some technical questions and behavioral questions. I was called the next day with an offer. All in all I would make sure you know specifics about the group you are going for and be able to use your experiences to show how you can add value. Remember to stay calm and be yourself.