It was 4 stages with estimation cases and longer case studies. Furthermore, an aptitude test After each stage I received feedback via a phone call. Overall, very pleasant and felt very welcomed by the interviewers.

1) Fit interview 2) Case interview - Got 12 minutes to solve a case, the interviewers left the room, and I then had to present afterward 3) Final interview Between the fit interview and the case interview, you will have to take an aptitude test. I did not do well on the numerical part of the test. This meant that the case interview was sort of a good cop/bad cop situation. I generally got a very good impression of the firm and its people - but the case interview was handled weirdly. Be aware of brain teasers - these are just about breaking down the problem into smaller parts.