I was contacted by a recruiter via LinkedIn, had a phone screen and then visited Google in Mountain View for an on-site. I had 4 separate interviews. I was told in advance that they would each be on a different topic (stats, coding, data analysis, stats + data analysis) but it turns out that each interviewer seems to evaluate based on all of the topics, so all four of the interviews involved some amount of stats and programming. he interviews were not very well organized, we started late, rush through one, and two of them were via video chat, which meant that there were some communication difficulties. Nobody told me in my schedule for the day or which interview was which, making it difficult to mentally prepare. The questions ranged from basic probability and statistics to more applied statistics. Some of them involved rather niche topics though, making it less a test of general knowledge than a test of whether the interviewee studied a particular area in advance of the interview.