I began with a phone screen, then received an invitation for an on-site interview. There were - technically - 6 interviews; one with HR, 4 technical, and one with the manager I would be working for over lunch. The process took about 4 hours in total (45 minutes per interview, with HR being short). The phone screen was fairly simple and short (about half an hour), and the on-site had much more interesting questions; only one was what I would consider a 'staple' coding question that it would be likely to have come across in another interview (I actually had used it a couple times when I was interviewing others in the past). The emphasis in the interviews seemed primarily about optimization and refinement - while the questions were not (for the most part) that difficult, the interviewers strongly pushed at improving solutions, catching edge cases, and fixing bugs, rather than implementing difficult or esoteric algorithms.