The loop at Meta has definitely evolved recently. The initial phone screen was standard algorithms. However, the virtual onsite was much more practical than I expected. They still have the architecture and behavioral rounds, but they also included a live coding and debugging session. They want to see if you can actually navigate a messy codebase under time pressure, not just memorize optimal solutions on a blank screen.

Started off with the internal referral and after a brief initial chat, I was invited to a technical phone screen, followed by on-site interview; it was 2 coding, 2 system design and 1 behavioral. Coding rounds was 1 medium and 1 hard LC Meta tagged, and system design interviewer was just awesome and asked a lot of creative follow-ups going beyond the traditional "oh what sort of caching mechanism would you build for this". I had a pretty good idea thanks to some mocks on the standard channels, did one on interviewing io and 5-6 system design on prepfully. My recommendation - keep practicing LC hard and a mock interview of each type at Prepfully, and DO NOT underestimate the behavioral coz this did as much for my leveling as the system design ones did.