I got recruited by AT Kearney's primary staffing agency. It was a series of phone calls and in person interviews.
1) Phone screen with a mid-senior level manager , went over behavioral questions and case interviews
2) In person interview: Behavioral, resume oriented, case interview
3) Case presentation: Solve and present a case
I had an excellent experience in the interview process. My phone screen interviewer then turned prep mentor (once i got selected to the in person interviews). As part of the phone mentor process they provided mock interviews for written and presentation cases. This was absolutely invaluable and it showed 1) they want you to succeed 2) they want you to be prepared
In person, the first case was medium-tough, if you have solved over 50 cases you can get the answer. But they dont care about the answer, its the approach. The like to hear your approach as that is a better indicator of your case solving nous.
The in person interviews are split into morning and afternoon sessions. If you get the morning 3 pack right (behavior, case, resume) you will get selected for afternoon presentation case. There was a 2 hour gap between the sessions.
The toughest part of the interview was the presentation case, they gave me about 15 pages of hard core data and about 18 questions to address. They provide you 1 hour to read, decipher, answer the questions, then you have to put them up in large presentation stick it notes so you can present to a partner and principal. They get about 1 hour to inundate you with questions, this process was equally rewarding and scary. They want to ensure you can speak for your numbers, you can show your work and show how you arrived at your conclusion while simulating client-like environment.
I have since accepted AT Kearney's offer and can say that the amount of encouragement and coaching i get is absolutely great, they truly care for your comfort and fit with the company to ensure we can focus on the clients. Its been 6 months since my interview and 3 months since i joined, i waited to post this so i can share my experience after i joined as well.