I'm guessing 2012 because I thought that was the year they stopped doing brain teaser interviews, which were very controversial at the time. Googling it now, the exact year is fuzzy -- like, they originally stopped in 2006, but only fully stopped around... 2011-2012? My evidence is this thread and its linked article: https://www.reddit.com/r/programming/comments/1gq72n/comment...

I received an offer from Google around May 2012. My interviews were long and numerous with interactive coding and whiteboard sessions. No brain teasers. Larry Page was still giving final yes or no on hiring.

no, but that is about when Larry and Sergey checked out (wasn't an overnight thing, took a few years).