First there is a brief screening interview. Then a first round interview with a case study component and a behavior interview component. The case study component is pretty basic, they asked questions like "What quantity should the company output" after giving a table of prices and predicted sales volumes. Final round is conducted on-site, a series of four sessions, one case, two behavioral, and on 'get to know what you'll be doing'. Again, the case interview wasn't particularly difficult, you do need to work fast. The behavioral interview is looking to see if you fit the consultant stereotype. Essentially ZS is just another consulting firm looking for just another consultant candidate.