How is their remote/work from home policy? How are the offices? Are they massive refurbished warehouses where hundreds of people constantly distract each other?
> massive refurbished warehouses
I wouldn't say "warehouses" --- the visual design is quite good, with a modernist bent. Frank Gehry designed the last few new offices.
But yes, the offices are very open. Fortunately, you don't have to be there in order to code.
I think the expectation is that you just be an adult about your work habits. Make sure that you're not slowing down the people you work with. It's up to you to figure out how to do that. One strategy is to just be in the office, but there are other options too.
(I'd say "teammates", but close collaborators aren't necessarily teammates at FB. You might work closely with someone every day and share only Zuck as the lowest common manager.)