YOE: 10 years
Current Position : Senior Software Engineer at well known company in Bay Area

This is my first FAANG interview. Not going to post exact questions due to NDA.

Phone Screen:
Both questions were LC Easy and Medium. Easy one array based and medium BST based. I was able to finish both of them with in 40mins and able to answer follow up questions. Feedback was that I did very good.

Virtual Onsite:

Coding round 1:
1 hard problem and was not from LC. Implement maze puzzle. Initially I struggeled a lot, but came up with naive approach and then made it optimal. There were a bunch of follow-up questions on the data structure internal implementation and Big O. I did average in this round.

Behavioural:
Usual Behavior/Leadership questions. The intervewier had a big list of questions that covered most workplace situations, conflicts and went through most of them. I gave as many examples as I could. I was grilled on cross functional team interactions - interviewer went deep and sought a lot of actions/clarifications. I did pretty good in this round.

Coding round 2:
2 LC Medium. First one array based and other one search related. I was able to solve both of them within 40mins in optimal way and I can say that interviewer was happy with my solutions. I did pretty well in this round.

System Design:
Very famous social media related system designn question. There were plenty of audio/video issues from the interviewer side and wasn't really communicative at all. Later interviewer called on my phone. Interviewer quite convinced with my approach and answers. I did pretty decent job and able to answer all follow up questions.

After two weeks I heard back from the recruiter with -ve news. I've requested feedback, but recruiter said unfortunately I can't provide more details and will touch base after 12 months. I heard that FB usually provides feedback. I've no idea what went wrong. Is anybody had similar experience ?