What do :prep-tasks ["javac" "compile" ["run" ":duct/compiler"]] in project.clj file of duct-pedestal-reitit-master template?

How can we setup template like this with deps.edn and CLJ?

I am not able to understand key concepts behind Duct and Integrant.

https://github.com/technomancy/leiningen/blob/master/sample.project.clj#L258-L262

IMO the key concept is that the declarative config is turned into running system.

Don't really know much about the deps.edn, but basically, you'll need to implement some kind of your own :prep-tasks

In deps.edn the equivalent would be a function that compiles Java code, then Clojure code, then runs -main with the argument :duct/compiler.

It’s there to allow keys that derive from :duct/compiler to compile static resources to be included in the final release.