My biased suggestion and would benefit from your C++ understanding is the Nix community (https://github.com/NixOS/nix https://github.com/NixOS/nix). More frank

My biased suggestion and would benefit from your C++ understanding is the Nix community (https://github.com/NixOS/nix https://github.com/NixOS/nix). More frankly, “best” is very subjective and you should find a passion or topic or task you are already interested and use that to guide your decision.