I don't think I'd call it amazing, but Facebook isn't as big as you'd think (especially compared to Google). It's around 3,000 total, with some fraction of that being engineers. Engineering currently makes up 64 of 402 open positions.
> Engineering currently makes up 64 of 402 open positions.
There are 64 unique job titles in Engineering (and 56 unique job titles in Technical Operations, which also includes software development job titles), but that represents a lot more than 64 (or 120) open engineering positions.
That's not to say that Facebook isn't as big as many people think, though.