I was being hired out of state, so this is probably not typical. I applied online via Slalom's website, and immediately (within 3 hours) was contacted by their recruiter who wanted to schedule a phone interview. After the initial phone interview, I scheduled my in-person interviews (I was traveling to Portland anyway). I was interviewed by 3 people, including the GM, the Director, and another consultant. Prior to receiving a formal offer, I was asked to have another phone conversation with the GM.
The two key things about this interview process: Slalom is really interested in the cultural and work environment fit of new hires. From a cultural perspective, most employees are from the big consulting firms and are looking for a more relaxed, less stress (and less traveling) environment. From a work perspective, the Portland market is small and the work can be less exciting than other metropolitan areas, so they wanted to make sure I was ok with that.