Dhall is nice that it can natively support configuration migrations via total functions. For example Config1 can be migrated to Config2 by applying a function t

Dhall is nice that it can natively support configuration migrations via total functions. For example Config1 can be migrated to Config2 by applying a function that always completes. It's also possible to constrain that function so it must accept Config1 and return Config2. Dhall supports functions from URLs and it's good to pin them using SHA hashes of their internal representation.