1. Bazel is a build tool similar to Make, Google is characteristic for its internal software development of tailor-made tools, Google now use it to build most of the internal software. Google believes that software is too slow to build directly Makefile, the results are not reliable, so built a new tool called Bazel, Bazel rules of higher level.
https://github.com/bazelbuild/bazel
https://www.bazel.build/
2.