Best teams to join at Facebook?

6 YOE. Have an E5 offer from FB (no numbers given yet). Recruiter suggests that if I give a list of teams to her I can talk to a few managers in those teams and maybe even "pre-match" before boot camp I don't feel like I really challenged myself as an engineer in my 6 years at Microsoft (was in Windows :(, should've left earlier). I want to grow specifically in backend/infra chops (basically corresponding to hard CS problems, I've been working too much on desktop UI) 1. What teams/product areas have the best backend/infra engineering talent? I'm looking for smart but high EQ people. 2.What teams/product areas should I avoid? Location, prefer in the city, so SF or Seattle (I heard FB SF is just instagram? is that a good org to join?)