> You'd prefer to allow composability in the middle and bottom layers (the modules) but have a different language on top? Absolutely. IMO, the top layer should

> You'd prefer to allow composability in the middle and bottom layers (the modules) but have a different language on top? Absolutely. IMO, the top layer should be a summary of what the configuration manager will be doing and should have the project-specific data in it. The rest should be reusable modules. When you let a full program language into the top layer, you inevitably get people trying to put smaller routines in the top level itself mixed in with reusable modules, which results in bloated spaghetti.