Efficient process throughout. First round interviews consisted of a case study and a market sizing study, with "fit" questions asked in the beginning. The case was of average difficulty: I think I messed up some of the reading of the data but it worked out well. Market sizing was fine, they are more interested in your assumptions, method, and your reaction to your final answer than in your actual numbers. I was in and out in less than two hours, so really efficient. Got an email the week after saying I was through to second round, which consisted of a written case and two interviews. The written case was hard: the calculations required take time and there is a lot of info to be digested. I messed up a lot of the maths but my analysis was fine on the whole, but be aware that you're not going to be able to synthesise all the info required so be open to thinking on your feet when your interviewer points you in a direction. The second case interview was easier than normal--the interviewer drove this, and it was mostly brainstorming with some (easy) maths: no summary. Third interview with a partner, and mostly fit, with some maths, structure and brainstorming thrown in. The latter two interviews were far less structured than in first round and really more about getting to know how you'd fit in Bain. I enjoyed the process and all the people I met, and have accepted my offer.