The interview process was 2 phases: A screening call, followed up by on 4 part onsite interview.
Screening call: We went over my resume and they drilled down into some of my previous positions to find out exactly how i contributed and what my responsibilities were - pretty standard stuff. They just wanted to see if I could talk intelligently about software development, and architecture
Onsite: there were 5 x 45 min interviews. 3 technical ones that tested 3 different areas: algorithms, design and architecture, and 2 that tried to gauge how well of a fit i would be with the company.
The questions themselves all seemed well calibrated. I think they effectively revealed my knowledge in the areas. And the interviewers were all great - they were welcoming, patient, and I never felt pressured by any of them.