Nix is similar to Bazel, supports distributed cache + build + CI (via Hydra), and has a huge amount of existing build support tools. It's not typically used as the only build system though; it's more like glue that wires all your build systems together deterministically. Build steps (derivations) are simple bash scripts executed within a sandbox.

The only catch is that while the language and tools are simple, Nix is really a pure functional language and you have to treat your build process like code rather than config. It's easy to go down rabbit holes...

(I considered Bazel but it's very half-baked and lacks all of Blaze's proprietary toolchain support.)

Cheers, will check it out

Its super simple to use for languages such as python or C++.