We're trying to do something very similar to what the OP proposes at our current company (Kurtosis), and we explored YAML, Jsonnet, Dhall, CUE, and general-purp

We're trying to do something very similar to what the OP proposes at our current company (Kurtosis), and we explored YAML, Jsonnet, Dhall, CUE, and general-purpose languages and eventually settled on Starlark: https://docs.kurtosis.com/explanations/starlark#why-did-kurtosis-choose-starlark-for-its-environment-definitions https://docs.kurtosis.com/explanations/starlark#why-did-kurt... BLUF: Infrastructure seems to live in this weird "configuration code" space between pure config (YAML) and actual code. You want reusable config, but you don't want to have to understand the complexities of a real codebase. Jsonnet, Dhall, and CUE all have the simplicity you want, but we found the DSL we'd need to write to be rough. Starlark hits this very nice balance of safety and ease-of-readability (and as a bonus is basically just Python). We've been very happy with it so far.