Recruiter contacted me after a referral from a Googler, former classmate. After first assessment, I was set for another interview with a current PM. The interviewer explained the overall setup and then asked questions about Google's major challenges going forward and what I would do to overcome them. He also through some quizzes at me, such as "You have 25 horses and a 5-horse race track. What is the minimum number of races you have to run to find the 3 fastest horses ?". He wanted the number AND the rationale behind the process.

You would have to do a hiring assessment first, then a recruiter screening follows. First round interview with the hiring manager. Majorly product sense and product improvement. The questions were not direct though.