Implementing a DDD project in Clojure - 2

One important thing I forgot to mention (even realize) in the first post is the applicability of the Dependency Inversion Principle for Clojure. In a DDD application adhering to Hexagonal Architecture the Domain layer is at the bottom of the dependency-chain. It has interfaces (Secondary Ports) implemented (as Secondary Adapters) in the Infrastructure layer, so the direction of dependency is the inverse of the direction of control-flow. In Clojure you can achieve the same with Protocols, but without application context and objects we need a Namespace (I called it registry) to instantiate the implementations and the Namespaces that use the Protocol have to depend on it. So through the registry the high-level Namespaces depend on the low-level ones. I don't know yet how to resolve it, if it's doable at all.