finished my Meta PM loop in March. targeting a role on the ads side but I talked to a few people on other teams too. writing this up because the PM loop is quite different from SWE and there's less good info out there for it.
the PM loop structure: product design / product sense (usually 2 rounds) execution / analytical (1 round) leadership (1 round) strategy (sometimes, depends on level and team)
for senior PM (L6 equivalent in Meta's leveling), all of these happened. for associate PM the loop is shorter.
product design questions I actually got: "design a feature to improve connection quality on Instagram for new users." "how would you improve Facebook Marketplace for buyers?"
the format is: define the user, define the problem space, prioritize a specific user segment and their pain point, generate solutions, prioritize solutions, define success metrics. they want you to go deep on one user segment rather than broad across all of them. I made the mistake of staying generic in my first prep and got feedback that I wasn't anchoring to a user.
analytical round: they gave me a metric drop scenario. DAU for a feature dropped 15% last week, what's going on. you need to think through: is it a measurement issue first, then segment by platform/geography/user cohort, then ask about product changes, infra, seasonality. I talked through it out loud and drew a tree on the whiteboard. they want structured thinking, not the right answer.
what Meta PM interviews are really about: ownership. they don't want a PM who presents options and waits for the eng or design team to decide. they want you to take a position. "I would build X because Y, and I'd kill it if Z metric doesn't move by Q." that's the register they want.
leveling signal: at senior level they expect you to identify when you'd push back on a business stakeholder and how. I was asked "the VP wants to ship this feature in 2 weeks, what do you do?" the answer they want is not "I'd comply."