Stage 1 was an aptitute test conducted by Aspiring Minds - AMCAT, the same test is used by deloitte for shortlisting candidates. It consists of Quant, Verbal, Logic Reasoning sections and an additional section to test how you work with a lot of data ( can not remember the exact section name) Stage 2 All candidates shortlisted after the first stage are eligible for appearing for a case study interview, in which the candidate is provided with a numerically intensive case study, post which the answers are discussed with a consultant in an interview. There are no complicated mathematical calculations to be made and they are looking at basic business understanding, they will guide you through all the questions in the case study. People are eliminated post this round. Stage 3 Is a behavioral interview which involves questions from your resume, based on your projects, past experiences in working as a team etc. Guesstimates and mathematic puzzles are asked during this session of the interview. Practice guesstimates from Case-In-Point book, pdf can be found online. Stage 4 is something you can call as the HR round where you're asked about Why ZS? If not ZS, where? Why consulting despite being an Engineer? Where do you see yourself in 5 years? Do you have any MBA plans? Just prepare these few questions and keep them ready! That was it, expect a lot of waiting time, the whole process took me about 12 hrs for the interviews, the test was on the previous day, you can find sample questions for AMCAT online, its pretty simple and tbh the easiest part of the whole procedure.