First round was the problem solving test or PST. Second round was two one hour case interviews. Interviews were interviewer led. Began with about 10 minutes of fit questions then the case, there were about 5 questions in the case including a numerical component. Nothing that you wouldn't expect. Everyone that I dealt with was extremely friendly and welcoming. Interviewers try to put you at ease and did not attempt to throw curveballs or play mind games. Atmosphere in the office is very intellectual and quite informal. A trend among all employees is that they are interesting, engaging people to talk to and have great people skills so this is definitely a trait that they look for. They are also very passionate about the job and are great at selling it to you. Overall it was a positive experience.