Two 1 hour interviews by Skype that were scheduled through the university. Both interviewers were great (one of them was Matei Zaharia :) ), and the entire experience was very smooth.

I applied through referral. The process was super quick. (actually the most responsive and fastest I've seen). I did two phone interviews in 2 days, and right after that there was one day long coding challenge, which was followed by on-site interview. Entire process took one week. I really liked how responsive the recruiter was. More than anything, every engineer I talked to was extremely brilliant and yet modest.