The interview process consisted of four 30-minute interviews in one afternoon. The first required me to present my current research and answer questions about it. Second was a structured case interview. Third was a behavioral interview. Fourth was an unstructured case interview.
Overall, the cases were relatively simple. I worked through them with the interviewers who seemed very supportive as I went. The unstructured case interview felt like more of a conversation/brainstorming session about what might be going on in a certain business case.
All four interviewers were exceptionally friendly and engaging. I had great conversations with them about my work, the cases, and working at ZS. This greatly contrasted to some other consulting interview experiences I had where the interviewers were noticeably cold and uninterested.