Nice write up, but wondering now what nix proposes in that space.

I've never used nix or nixos but a quick search led me to nixops, and then realized v4 is entirely being rewritten in rust.

I'm surprised they chose rust for glue code, and not a more dynamic and expressive language that could make things less rigid and easier to amend.

In the clojure world BigConfig [0], which I never used, would be my next stop in the build/integrate/deploy story, regardless of tech stack. It integrates workflow and templating with the full power of a dynamic language to compose various setups, from dot/yaml/tf/etc files to ops control planes (see their blog).

[0] https://bigconfig.it/