First round interviews (2 interviews - 1 fit and 1 case) and final round interviews (3 fit,1 case, 1 presentation). The cases themselves were relatively straightforward, with a strong focus on maths (probability + standard maths). I felt that there was a strong emphasis on fit particularly in the final round given that it was difficult to differentiate the best candidates from simple cases. I also had an interviewer who was socially awkward (not sure how she made it to Oliver Wyman).