Not with Bazel (on Linux or Mac at least). It builds everything incrementally. If inputs that go into the build node did not change, they won't be rebuilt. You

Not with Bazel (on Linux or Mac at least). It builds everything incrementally. If inputs that go into the build node did not change, they won't be rebuilt. You almost _never_ fully recompile, and with a cache incremental builds almost never take more than a couple of minutes. Google builds everything it runs from source, including things like compilers, runtimes, stdlibs, etc. Imagine if every engineer had to rebuild everything from the kernel up from source on every check-out. That wouldn't work.