If you are referring to a caching distributed compile cluster, most companies with large codebases are using one (or should). It helps a lot and can make the difference between taking half a day for a scratch make (i.e. unusable) to getting down to 10 min.
There are open-source ones but I'm also aware of at least two internal, custom-developed ones.
There are open-source ones but I'm also aware of at least two internal, custom-developed ones.