While not designed to be a system package manager, Conan works in a very similar way for C/C++ package management, and it's great. All binary packages live in the cache folder, identified by a hash of the particular permutation of inputs used to build it. It even supports recipe revisions, so if the recipe (build script) changes, you don't have to worry about changes in the generated binary since you can use a lock file to keep using the specific revision of that build script that you know works.
pnpm for Node packages also has a similar design. Once upon a time, it cited Nix as a source of inspiration in its docs!
I hope that basic design continues to propagate. Better-behaved package management for language ecosystems is easier to work with for Linux distros, including NixOS. :)
