Meta Production Engineer interview questions

I was contacted by the recruiter cold, and he asked several technical questions to see if my experience matched the job requirements. After that there were two scheduled phone interviews, one for programming and another for unix system internals. The interviews were as in-depth as you could go, so the questions would identify the boundaries of your experience and knowledge without making you feel lost. They are definitely looking for deep technical knowledge.

Two phone interview - one algorithms and one systems. 4 rounds onsite - one behavioural, one algorithms, one systems and one systems based coding round. Lunch was with an employee which was not an interview