The process:
1) Online application.
2) Contacted by HR recruiter via email within 2-3 days.
3) 30 min HR phone screen that asks questions around motivation to join and lays out the process and salary range.
4) Optional 120 min+ case interview coaching WebEx (offered twice a month to all candidates).
5) 60 min 1-on-1 phone coaching session with firm alum for phone case interview.
6) 30 min go/no-go phone case interview with a firm alum.
7) 60 min 1-on-1 phone coaching session with current firm consultant for 1-on-1 case interviews.
8) 2x45 min 1-on-1 in-person go/no-go interviews in the same day at a different office than the one you applied to (1 could be via video conference in a room in that office). Each interview is: 5 min background exchange and ice-breaker + 10 min personal experience (1 prepared story highlighting leadership, conflict management, influence, etc). The format is: I want you to take some time to think of a story that highlights your ... then you pretend to think about it for 10-20 secs and start telling. Half way through your story the interviewer will interrupt and ask for a random detail. + 30 min case interview.
9) 3X similar interviews to #8 in the same day at the office you'll be joining. These should, but not always, include partners.
Note: some interviewers will try to distract you and/or act rude (e.g. check their phone/laptop while you're talking or constantly interrupt you). This is supposedly done to test your reaction to a difficult client!
My experience: One of the best organized HR teams I ever interacted with, despite the process being one of the most inefficient and redundant I've ever seen. It's a mutual waste of firm's resources and candidates' time (and money for those seeking paid coaching). I personally felt the interview process was 1-dimensional, too naive, and easy to game with enough practice and access to google search. I constantly felt like my industry experience worked against me and that I needed to turn my memory off and approach the case the way a fresh college grad would (and for some odd reason without access to a calculator). I finally understand why the firm gets so many applicants, rejects so many, and manages to retain very few. I personally decided to halt the process after the 1st in-person round (for better industry options) and later received the feedback that my case performance didn't meet the bar to move to round 2 anyways.
My advice to candidates: If you're an experienced candidate, the implementation practice may seem like a perfect way to join a very prestigious firm and at the same time put your industry experience to good use. Also, if you've just earned a part-time or executive MBA, it may seem like a ticket to a job typically reserved for full-time ivy league or M7 MBAs. The truth is: 1) The interviewers absolutely don't care about how much experience you have and they won't even ask you questions about it. So think carefully about how valuable you will be to the firm as opposed to other companies in the industry. 2) These positions pay about $30k less than their superior associate (generalist) cousins. So think again! 3) These positions involve heavy Monday-Thursday travel every week for 9-18 straight months per engagement. 4) Even though it's advertised as partner-electable, all the implementation engagement managers and associate principles I interacted with were associate (generalist) hires who were later promoted into the implementation practice. I met no one who made it past Senior Implementation Coach. 5) The case interview is still "ALL" what matters - even if the recruiter tries selling you on the fact that you've been selected due to your outstanding experience or wonderful career achievements. Unless you've worked as a consultant or have previously practiced case interviews, you'll need to invest many many hours in preparation. The current process treats every case interview the same regardless of the position you're interviewing for (i.e. generalist vs experienced). Which means your interviewers will be judging you based on the bar set by many full time and less experienced candidates who have the time and resources to practice and perfect their case interviewing skills. The few coaching sessions the firm offers would hardly move the needle for most experienced candidates; so carefully weigh out the pros and cons before you consider applying and committing time and effort into the process.