Meta Data Scientist interview questions

First a brief introduction of yourself. Then why you choose facebook. The following is an online coding question using mysql. Then question about like/dislike system in the facebook. How to choose emotions and any problems in the A/B test. This question is quite hard and I didn't get it until the interviewer gave a lot of hints.

I applied online in late December and then spoke to a recruiter for about 15 minutes in early January. I was scheduled for an in-person interview in mid January where I interviewed with one data scientist in a 1:1 interview for an hour for the first round. Another recruiter then called me for a 30 minute prep for the 2nd round. The final, 2nd round interview was about 5 weeks later in late February, with 6 data scientists over 4 hours in the afternoon. I got an offer but it was for a lot less than I was expecting, and we couldn't bridge the gap enough for it to be worth it. Everyone seemed relatively nice, although I could tell that a lot of the questions are really designed to trip you up, like they want you to miss some detail or edge case. My advice would be to pay attention to every little bit of minutiae regarding the question, make sure you're staying on task, write on the whiteboard, and explain your thoughts. Industry word is that data science at Facebook is not what it once was and is more of a product data analyst role now, so make sure you're really into Facebook products because that's what you'll be analyzing. Also, I didn't get a single question about dice, cards, or any other brain teaser type questions. All these mentions of NDAs are missing the point of Glassdoor, people can be a little more verbose than "various questions". You can't trademark an interview question or claim it's a trade secret.