Functional programming is often seen as the domain of academic or hobbyist experimentation, but Clojure and Datomic challenge this perception. Built with production in mind, Clojure offers the flexibility of a dynamically typed language while maintaining the rigor and composability of functional paradigms. Paired with Datomic’s immutable, time-aware data model, this stack powers some of the world’s most demanding systems, from fintech to e-commerce. This talk explores how Clojure and Datomic overcome traditional concerns about dynamic typing and functional programming, delivering unmatched developer productivity and system resilience in production environments.