Potential job was about predicting number of servers required or something like that. I was recommended by a friend's friend who apparently worked there. Google contacted the day they saw my resume and did two quick phone interviews verifying my basic background.
In the third interview which was highly technical, they asked a bunch of techie things including what an inode was. Whatever answer I gave about inode was apparently OK, as the interviewer proceeded to ask me how I would repair a faulty inode.
Since I did not know the answer, I honestly said I do know and joked that I would "google" for the answer. My pathetic attempt at humor did not sit well with the interviewer and was told that I did not pass the current interview.
Fixing inodes or other hardware/software problems is certainly something that needs to be done, but I did not buy the interviewer's assertion that everybody in Google knows how to fix inodes. For making predictions about server needs, failure rates are just one factor to consider and the time needed to repair them.
Whether a prediction manager needs to know the low level details of fixing inodes is questionable in my mind. I just assumed that Google interviews a staggering amount of people and reject a large portion of them for the smallest of reasons (like how astronauts are selected). It also seems they hire people for one thing, but that does not preclude them in deploying them in totally different positions. Otherwise there was no reason to ask me techie questions.
What surprised me was how fast they moved, how upfront they were about overall interview process, and how they asked about non essential questions from my perspective.