I applied for the job directly on the careers page of the website, then had a phone screen, an interview over Google Hangout, a case question interview, completed a take-home assignment, was flown out for 3 on-site interviews, had one last Google Hangout interview, had my references checked, and then received an offer.
The entire interview process took about 3 months from my submitting the application on the website, to receiving the offer, so it was a bit long, but it may have been due to the fact that 1) The open job postings were changing a lot at the time (I actually later received a different job than the one I applied for) and 2) I was interviewing from across the country, in NYC.