Hands-On Reactive Programming with Clojure

Reactive applications respond to events, changing data, and work happening in parallel. Hands-On Reactive Programming with Clojure makes those ideas concrete, moving from the principles behind reactive systems to examples built with Clojure and ClojureScript.

Konrad Szydlo and Leonardo Borges begin with functional reactive programming and compositional event systems, then put the concepts to work in applications involving streams, interfaces, networking, and cloud services. The result is a practical exploration of how to structure software that reacts to changing inputs.

From event streams to working applications

The opening chapters establish the language of reactive programming: observables, signals, events, and time-varying values. From there, the book examines Reactive Extensions and shows how to compose and transform observable sequences, with attention to error handling and backpressure—important considerations when incoming work can outpace processing.

Explore Clojure’s asynchronous tools

Examples using RxClojure and show different ways to model asynchronous data flow. The authors also build a small compositional event systems framework and use Reagi in a ClojureScript game, giving readers several approaches to compare rather than treating reactive programming as a single technique.

Apply the ideas across software projects

• Build a stock-market monitoring example and work with rolling averages.
• Explore reactive approaches to web interfaces using ClojureScript, Om, and React.
• Use futures to fetch data in parallel and consider blocking I/O.
• Design a reactive AWS API and dashboard around cloud resources.
• Examine microservices, testing reactive applications, and Clojure concurrency utilities.

For developers with Clojure experience

This second edition assumes basic knowledge of Clojure. It is suited to developers who want to understand event-driven and concurrent application design through worked examples, and who are interested in the choices and trade-offs among reactive libraries and patterns.

For a hands-on look at reactive programming in the Clojure ecosystem, this book connects foundational ideas with the code and architectural problems they are meant to address.