1 month long. did first round with HR who was really nice and helpful. Did second behavioral round with senior consultant who was also nice. Did super day following week with 1 principal (behavioral), 2 senior managers (behavioral) and a manager (case). I have never had such an awful experience during a superday. 1 interviewer was 30+ mins late to our 45 min interview. An interview that was supposed to be behavioral turned into a case interview. All interviewers were concerned about my part-time graduate program. If you didn't want to hire me, why waste my time like that?