First I was asked to take 2 online tests (1 IQ test + 1 Tech skills test) which lasted approximately 1 hour, then I received a call from one of the Mckinsey recruiters. The call lasted around 1 hour even though they said it will be only 30 mins. The recruiter kept asking the same / fairly similar questions throughout the call, I assume to find out whether your answers are consistent. It was very long and exhausting. Then I was invited to a full day assesment center. I was there with 5 other applicants, we were doing both group and individual excercises. The group excercise felt more like a reality show, everybody trying to put himself on the spotlight as much as possible while the hiring committee monitors your every step . Individual excercises were mostly fake e-mail / phone requests. I'd say the issues you were asked to resolve were quite easy if you have at least some experience with tech support (connectivity issues/ printers / slow pc etc). After that they made a decision which was provided individually and either sent you home or made an offer (dont know how many people got the offer, but not more than 2). As it is a consultancy company the enviroment is very formal and "noble", even though it was interview for IT position everybody was wearing a suit. Be prepared that they are looking for people with the right "american" attitude on the phone (at least that's what I call it) meaning your main goal isn't only to fix the customers issue asap but also make him feel good, happy/ calm, relaxed etc during the call. So If you want to succeed I'd definitely recommend to focus on some sugar talk as well. That is where I failed actually, at least that s what they said in the end. The overall impression would be a bit snobby environment and pointlessly overdoing the hiring process for fairly simple position.