Two rounds of interviews with three 1h interviews in each round. The first round consisted of a standard personality/fit interview, a qualitative case interview, and a quantitative case interview. For the personality interview, I had friends rejected because they did not really connect to the firm - so make sure you understand what S& focus on - i.e. commercial due diligences and strategy work. Understand the difference between strategy consulting and management consulting, and that CDDs often are short intense projects while strategy work often is more in-depth, and then incorporate those facts into why you want to join S& and not any other consultancy. The qualitative case was a very standard interview-led M&A case, do some standard case practice and you will be perfectly prepared. The quantitative case had a pretty difficult guesstimate - so you might want to practice some wild structured estimations. It also had a pretty easy but tedious part where I had to do a bunch of multiplications for 30 minutes. They test for speed and accuracy, but the calculations were not advanced. The partner round was much more personality-oriented. Lighter cases in the last 15 mins of each interview (one guesstimate, one industry outlook discussion, one standard case).