Meta Data Scientist interview questions

I got a phone screen for 15 mins from HR, walking through my resume and checking about my visa status. It is very easy and after that, we schedule for the next round for a technical screen.

A recruiter reached out to me through email for a data scientist position. I was not sure if I wanted to work at fb at the beginning. So the recruiter let me join a facebook hosted event where I could talk to some team members, which is nice. However, I didn't like the people I talked to. For some reason I get the impression that they are not very friendly and they don't seem to provide much mentorship at work. Anyway, I still decided to start the interview process. First round is a phone interview with a data scientist. She asked me some sql questions. I would say it is medium level difficulty. Then one programming exercise, which is like leetcode easy level question. Then I went to the onsite interview. 1st round: Interview with 2 data scientist. Mostly sql questions. It covers topic like row_number, case, joins. Then follow by simple data analysis questions where you need to check the data distribution. 2nd round: interview with another data scientist. 1 medium to hard level sql questions. Then she started to ask me some ab testing questions. I told her that I never did any ab testing at work, but I guess she thought I should have known it. Well I tried my best to tell her my answer, then she started to told me something like "oh you need to read your book. You didn't prepare at all". I was like okay sorry I didn't know the answer. Even though I didn't want to take it personally, but that is a really hostile comment. 3rd round: coding exercise with 2 data scientist/ engineers? They asked me 2 questions. 1 for array partition and 1 for counting the word frequency in a file. Not too difficult. But you need to ask for details on the requirement. Then I had lunch with recruiter at noon in campus. 4th round: interview with hiring manager. Mostly business questions and behavioral questions. 5th round: interview with product manager. All he asked was behavioral questions. I had to say those are the most weird questions I got asked. One question is like "do you have any experience where your job is completely different than in the job description". I told him sometimes I will work on different projects. Then he said "oh I am asking do you have experience of working on a completely different role". This sounds like a red flag to me. I mean if you hire a data scientist but she ends up doing PM or developer work, that is not a good thing. I cannot imagine why a company will want to do that. But it sounds like this is something that happened in facebook based on our conversation. I really don't understand what is the intention of this question. Overall, I don't like facebook's culture. I know people in facebook are very smart, but I don't think I will ever want to work at facebook. Not a very friendly work environment.