I've always admired McKinsey & Co. but this interview process is a tad much. While fairly straightforward in terms of procedure, the recruiter handling the process was at times rude, unprofessional, and unresponsive.

Phone screen, followed by SHL exam, followed by two first round case study interviews and three final round case study interviews with senior partners. Questions were mostly on point and what was prepared for me except the 2nd of the final interview in which business questions were asked (What is a lifetime expected value and how is it calculated) which I was told would not happen as a business background was not necessary for the role. The interviewers were nearly always up to 40 minutes late, 3 or 4 interviews were cancelled, and all were rescheduled at some point in time. They said they were trying to rush the process but it took over 3 months.