Clojure is a new dynamic language targeting the JVM, the .NET CLR, and JavaScript. Clojure builds on the long history of Lisp-based languages while embracing modern platforms and pragmatic design.

This talk is an introduction to Clojure and its core concepts: immutable values, functional programming, code as data, software transactional memory, generic data structures, and protocols.

Having an expressive programming language like Clojure comes with a price: it’s not always clear how programs should be structured. Without classes in the traditional OOP sense, what are the fundamental building blocks of an application? How do we divide up our source files? Where do different kinds of state and behavior “belong”? These problems become more acute as programs grow larger and more complex.

This talk assumes some basic knowledge of Clojure, and will present patterns for building large Clojure applications out of modular components. Topics include:

• Protocols and records
• Dependency injection
• Managing startup / shutdown of components
• When (not) to use dynamic binding
• Interactive development workflow
• Testing and mocking