I was looking for a change and luckily a recruiter reached out on LinkedIn and it started off with the standard recruiter screen, understanding my devops background etc. first phone round - was all linux troubleshooting and coding etc. Next round was more linux, more coding, also got a system design and a networking round because the team was of network production engineers. questions involved standard linux troubleshooting and memory to cpu to disk io and in-depth understanding of system conepts (threads, virtual memory, mmu, signals, file systems). There are quite debugging questions too so be very prepared. I did LC and hackerrank along with a couple mocks on Prepfully for the PE topics and interviewing io for coding. Mocks did help a lot to be precisely prepared on what's coming. It's been about a month here at Meta and it has been a great experience so far.