I applied through a recruiter. The process took 2 weeks. I interviewed at Google (Mountain View, CA) in Mar 2011
Interview
Liked the fact that they emphasize hiring great candidates and have the processes in place. Recruiter contacted. Initial Recruiter phone interview. Then Hiring manager phone interview. Visited campus and talked to 5 other people. Interviews went well... Job role changed due to an internal re-org post interview....So no go...
The process took 1 day. I interviewed at Google (Bengaluru) in Mar 2008
Interview
The phone interview went very quickly. He was very nice and asked about my specific talents, things I enjoy doing, and projects I’d worked on–especially those I listed on my resume. He asked about the ray tracer I wrote in college, since he had an interest in that. He also asked some general questions about the stuff I do for work. Then he got into the technical question. It was an interesting problem, and I asked follow-up questions, talked out loud, wrote things down in front of me (and told him what I was writing and why). I immediately thought of the naive solution–always a good place to start. He was interested in the asymptotic complexity. I knew there were better ways of doing it, so I started thinking of optimizations to the algorithm, trying to come up with ways of caching information, reusing previously-computed values, etc. He gave me some gentle prodding, and I think I understood immediately where he was going. I answered the question fairly well, I though.