The interview process was very similar to other management consulting interviews. There are 3 rounds of interviews, 1) meet with 2 staff consultants, 2) meet with a Sr. Manager and a staff consultant, 3) meet with the managing director. Both first rounds are very similar in that you discuss your resume in greater detail, they ask you clarifying questions, and then you go into a brief case study. I would not stress about the case study if you have either worked as a management consultant before or you have prepared yourself by doing case study prep work. Compared to my two previous employers which were a Big 4 consulting firm and the management consulting department in a large healthcare company, I found this case study on the easier end of the spectrum. The third round consists with meeting the managing director which is more of a personality and fit based interview. The style is more of an informal conversation than an interview.
I would recommend that you make sure you can speak clearly and concisely about your previous work or school experience and that you have prepped well with case studies and you should be fine.