The initial interview consisted of a phone interview from the company recruiter. He asked basic questions off my resume which were not too difficult to answer. He said that if I made it to the next step that I would be expected to come in and have a one to one interview. I was warned that the interview would consist of (besides the normal questions on my past experience) brain teaser questions to test my thinking. I did get invited to the next interview in person and the interviewer was very nice, seemed to be extremely well versed on my background and asked an estimation question such as how many golf balls would fit into a bus sort of thing. My impression of the googleplex is that everyone is super intelligent, well education and searching for people who fit in.