MongoDB uses Scons to build their product, or did when I was there. MongoDB is coded in respectable modern C++, with an admixture of Java bad habits and a history of Google Style pessimization.

Among the most used articles on MDB's internal wiki is "Scons: It's Not That Slow!"

In fact it is really quite, quite slow, but a universally popular add-on (not officially "supported" when I was there), is a Ninja build scheduler that is blindingly quick.

So, the slowness only manifests when you need to recalculate the dependencies, which doesn't appear in the typical edit-build-test cycle. With Ninja, combined with Ccache and a distributed build tool (whose name escapes me ATM), coding at Mongo was not bad.