Mckinsey has a notorious reputation for its grueling interview process. I say it's all relative. Understand the candidate pool from which they chose is highly selective and without a doubt very intelligent. Just because you have graduated from Harvard (or any other Ivy) does not make you a shoe-in, and just because you have never attended one does not disqualify you either. I did not attend an Ivy and was hired as an Engagement Manager, my fiance graduated from Harvard and was not (however she was hired by The Boston Consulting Group). The interview process is as much an endurance test (to see how you perform under duress and maintain an effective thought process) and as a way to see how well you can execute and convey a well structured thought process. That thought process has to be both specific to the case without deviating to much on minor details, yet broad enough to account for any unexpected curve balls. The latter is where I have seen even the brightest individuals fail. The end product is the major concern especially with case studies. It is so easy to go off on a tangent with specifics (of course I only learned this after having received feed back from the interviewers - they commended me on my ability of not straying while still taking into account particulars and I quote "We can't give you any improvement advice; please continue in the same manner in the final round"). Anxiety is a major factor in the interview process... keep a structure and actively listen during case studies as keywords will make or break you from proceeding with the interview process. Mckinsey is also very thorough when selecting a candidate as they will comb through your entire resume to ensure it is not over inflated - know it inside and out and be able to go into a lot of detail. They also what to make sure that you "fit" into their corporate culture so a multitude or personality gauged questions/ scenarios are to be expected all through out the process. Keep good and effective notes because the last thing you want is a simple miscalculation to disqualify you (as in the case of my fiance and she holds a Ph.D in Econometrics). Their is no secret to being hired. You’ll be judged less on specific answers to case questions than on the method by which you arrived at them. In other words, you’ll be judged on how you think. I should also point out that creativity plays as large of a role as is being analytical. They want someone who can combine an intellectual and creative approach to problem solving with practical advice on how to put the chosen solution in place.