Preface

RxJS or Reactive Extensions for JavaScript is a JavaScript library designed to simplify working with asynchronous data flows, orchestrating events and sequences of data over time.

However, there is a belief in the community that RxJS has a steep learning curve, despite its amazing capabilities. One reason why RxJS has this reputation is that most tutorials, books, and online materials focus heavily on RxJS operators. These resources explain how each operator works in depth, with accompanying visuals. While these resources are really helpful and essential when starting to learn RxJS, developers may still face challenges such as debugging and optimizing RxJS streams, testing RxJS streams effectively, managing reactive state, fully adopting a reactive paradigm, and identifying the correct RxJS operator for real-world scenarios.

RxJS Cookbook for Reactive Programming takes a slightly different approach. This is a full stack book that emphasizes building modern web applications using RxJS techniques, patterns, and operators that naturally fit specific scenarios. Each chapter is composed of practical recipes that offer solutions to a wide range of challenges, spanning from handling side effects and error resiliency patterns in client apps to creating real-time chat applications and event-driven backend microservices.

As you progress through the book, you will develop a profound understanding of the potential of reactive programming in complex real-life scenarios. This book empowers developers to seamlessly integrate RxJS with popular web development frameworks and libraries such as Angular and NestJS, serving as an invaluable guide for developing web applications that are modern, progressive, resilient, responsive, performant, and interactive.

By the end of the book, you will have mastered the art of reactive programming principles, the RxJS library, and working with Observables, while crafting code that reacts to changes in data and events in a declarative and asynchronous manner.