Hi, today's my turn to share the interview experience I had with Facebook recently. It all started in October 2019 when a recruiter reached out to me. I had an initial phone screen. Was asked 2 LC medium questions. I will not disclose exact questions due to NDA but 1 was an array related one and 2nd was checking versions(variation).
I passed it and was moved to onsite. Anyway, I felt i was not prepared for my onsite so I took 3 week's time.Recruiter was happy to give that and so my interview was supposed to happen in early December. Anyway, the recruiter reached out to me around late November saying that the position had gone on hold and so my interview process was put on hold. I was contacted by her again around mid Feb when she asked me the position had reopened and wanted my availability for onsite directly(as I had passed phone screen before). I sent in my dates and finally, the dates were decided for March 10th. Anyway, COVID-19 situation kicked in and my physical onsite was changed to virtual one. Happened on March 12th. I had read that one should take a good sleep before the interview and for me, my 3 year old woke me up in the middle of the night before my interview(he probably had some nightmare). While he went back to sleep, I really couldnt. Anxiety was killing me equally. Anyway, I appeared for my interview around 11 am the next day. BlueJeans acted up and I had a nightmare getting that initial thing set up. I had a heavy head (which at the time I did not realize). For first round, He asked me 2 questions:
One was a variation of getting 2 keys with sum similar to target
Second was variation of how to sort k sorted arrays
I failed both terribly . Could not come up with a good solution(I explained it very well though).
2nd round was behavioral which went good along with that coding question (LC easy)
3rd round was where I suspected my failure reason resided. I was asked one LC medium. I knew I had seen it before (not realizing where at the time). I did very well, feeling my first coding round was a mess, this may make things look better. 2nd question was Binary tree one with some priority queue solution. The problem was the first question on this second round was exactly same as my telephone round and I totally could not recall that partly because it was around 5 months back and partly I was nervous. Anyway, both questions went really well and even though I could not solve the second question completely, I explained him the time and space complexity very well and he seemed to be quite happy.
System Design was the best I suppose. I was asked very common Facebook functionality(which I had practiced with a peer) and so I had some food to talk about.
After 1.5 weeks, I received a call which was very vague and not specific. However, she did mention to me that the feedback was not begative due to one round. It was multiple rounds. This is something which I could not really understand as my system design and behavioral went really great.

I will retry again in sometime. I had solved 20 LC Hard, 50 LC medium