Welcome to the world of Bazel!
In case you haven’t heard about it, Bazel is the open source version of the build system used at Google (Alphabet). To give a sense of scale, Bazel was designed to solve some of the core problems of building at Google, namely, having to build literally millions of lines of code across a multitude of languages, efficiently and correctly, for multiple platforms (e.g., server, mobile, desktop) and different hardware architectures.
While the build system was initially internal to Google, it was released to open source a few years ago. Since that time, it has continued to evolve ...