The first round interview was very typical of what I would expect for a consulting firm. There were two half-hour interviews, one behavioral and one case-based. The case interview was significantly less quantitative than I expected though. What I noticed most though was that the two interviewers were very friendly, supportive, and open. I figured ZS had sent their happiest people to recruit at my school. I was right. The final round at one of their offices was a very different experience. I had four interviews, an individual presentation, and a lunch. Here, nearly everyone I met was open about their experiences at ZS, and none of what I heard was good. I was told that it was quite a grind, and everyone who talked about how ZS was very stingy compared to other firms when it came to expenses. The people I met there really seemed bored with their jobs, and weren't the most engaging I had met. Three of the interviews I had were behavioral/fit, and one was a highly quantitative written case. This was very different from what I expected, as most firms prefer a back-and-forth discussion. The best thing I can say about ZS's final round interview process is that the feedback was great. When I was called and told I didn't get the internship, the interviewer told me exactly what I had done well and what I had done poorly. Had I decided to apply again for a full-time position, this really would have helped me.