bazelbuild/bazel ? reverse-engineered prompt

I need you to build a tool for me to fix our company's slow and unreliable builds. The goal is to create a build and test system that's extremely fast and correct, even for very large projects.

The main thing is that it should be smart about incremental builds. It should only rebuild the specific parts of the code that have changed, using advanced caching and running things in parallel to speed it all up. Our projects use a mix of languages—Java, C++, Go, and we also build Android and iOS apps—so this tool needs to support all of them from the start.

It should be scalable enough to handle a huge monorepo and run on Windows, macOS, and Linux. I also want it to be extensible, so we can add support for other languages or platforms on our own down the road.