Several rounds of interviews, initially with less senior employees and Recruiting. Final round interviews with Directors, preceded by final round dinner the evening before.
The interview process is tough, consisting of 1 phone and 4 case study interviews with Managers, Principals and Directors. Regardless of how tough they were, they were all in all an excellent development experience and generally one of the more enjoyable interviews I've experienced. The case studies are not the typical strategy consulting examples, being more focused on the practical, operational side that the firm prides itself on. After the 2nd round of interviews, a social with members of the firm were held for the top candidates to really see what the firms all about!