I seem to find many sources that Googlers spend heaps of time waiting for test runs. Apparently they're required for about everything you do with code at Google and are the but of dozens of jokes.

All of which makes me think that maybe Google's internal building of code isn't that fast. Or perhaps it's fast, but only in relative terms (as in you're still waiting a few minutes for hello world, but huge programs build "fast", as in a few dozen minutes)

I did test it on hello world, and euhm ... It's not fast. The first build of it is horribly slow (double digit minutes, wtf is it doing ?). Second build is "fast" which should be understood to still be double digit seconds. Running the same program in VSCode and just compiling it with the system-installed compiler is so fast you see the output before the VSCode has finished drawing the terminal window.

Reading the site I also get the impression that Bazel's singular focus is correctness. They don't mind things being ridiculously slow if it increases the odds of being a correct build.