Refactoring Java-Style Code into Functional Clojure

HN repeatedly recommends it as a fantastic demonstration of procedural, OOP and FP approaches to the same problem, and of functional core and imperative shell.

Rafal Dittwald's Clojure/north talk shows how to move from writing Java-style code in Clojure to thinking in data-driven, functional terms. He walks through a JavaScript example, refactoring imperative code step by step into a functional core.