There are some deployments in the industry already. AFAIK, Logicblox employs Nix creator. Both Nix & Guix are past proof-of-concept stage. In particular, I've

There are some deployments in the industry already. AFAIK, Logicblox employs Nix creator. Both Nix & Guix are past proof-of-concept stage. In particular, I've found Guix very elegant, simple and useful.