Meta Developer interview questions

I was local to the Facebook offer so they did the screens in person. The first one did not go very well, but went well enough to get a second chance (as opposed to a full interview). The second one went better and I was invited back for a full day of interviews. They were able to rush the process since I had other offers. The full day interview was 4 interviews. 1 system design question, 1 manager interview ("Tell me about a time..."), 2 algorithms questions. Everyone was welcoming and enthusiastic, so that made the stressful process easier. I got a call from the recruiter about 4 days later telling me they were not moving forward with an offer. A bit disappointing and it wasn't entirely clear why as I thought the interview went well. I was interviewing for a smaller office so maybe that made a difference.