One guy was literally yawning all the time at around 11AM, which is very unprofessional. I was like, dude, doesn't Google serve coffee or sth?
I won't share specific interviews questions (I don't think they actually help much), but I will share some of my observations (which may not be 100% true):
1) Google seems to maintain a pool of interview questions. I was asked 2 of the same questions listed on glassdoor. But sometimes the interviewer just make up questions on the fly.
2) On-site consists of 5 rounds, 3 peer PMs + 1 PM director + 1 engineer, you'll have lunch w/ a lunch buddy after the first 3 peer PMs (food is actually so so). Meanwhile, your recruiter will gather quick feedback and make a snap judgement about whether to proceed w/ the PM director and engineer. If you don't make it to the after-lunch session, it is a ding for sure.
3) You need at least one 'strong hire' recommendation from the 5 rounds. It is not unusual for someone to get 5 'hire' recommendation but get dinged. So try very hard to really impress one interviewer.