Meta Sr. Software Engineer interview questions

Very social, they were very nice throughout all the interview. Everyone made you feel like they really appreciated you. They were in continuous contact through the interview process, which included phone interviews, technical interviews, and an all-day interview marathon (by video chat / shared coding).

Telephone interview with the recruiter for about 30 minutes, I talked about what I do and the recruiter talked about the role, in the same phone call I'm informed that I will be moving to the next stage. The recruiter then gave me an overview of the on site interview process. The onsite interview was good, the senior engineer I met was friendly. However I was dully unprepared and couldn't answer the question at all.