Book Image

Domain-Driven Design with Java - A Practitioner's Guide

By : Premanand Chandrasekaran, Karthik Krishnan
Book Image

Domain-Driven Design with Java - A Practitioner's Guide

By: Premanand Chandrasekaran, Karthik Krishnan

Overview of this book

Domain-Driven Design (DDD) makes available a set of techniques and patterns that enable domain experts, architects, and developers to work together to decompose complex business problems into a set of well-factored, collaborating, and loosely coupled subsystems. This practical guide will help you as a developer and architect to put your knowledge to work in order to create elegant software designs that are enjoyable to work with and easy to reason about. You'll begin with an introduction to the concepts of domain-driven design and discover various ways to apply them in real-world scenarios. You'll also appreciate how DDD is extremely relevant when creating cloud native solutions that employ modern techniques such as event-driven microservices and fine-grained architectures. As you advance through the chapters, you'll get acquainted with core DDD’s strategic design concepts such as the ubiquitous language, context maps, bounded contexts, and tactical design elements like aggregates and domain models and events. You'll understand how to apply modern, lightweight modeling techniques such as business value canvas, Wardley mapping, domain storytelling, and event storming, while also learning how to test-drive the system to create solutions that exhibit high degrees of internal quality. By the end of this software design book, you'll be able to architect, design, and implement robust, resilient, and performant distributed software solutions.
Table of Contents (17 chapters)
Part 1: Foundations
Part 2: Real-World DDD
Part 3: Evolution Patterns

Chapter 9: Integrating with External Systems

Wholeness is not achieved by cutting off a portion of one’s being, but by integration of the contraries.

– Carl Jung

So far, we have used DDD to implement a robust core for our application. However, most solutions (by extension-bounded contexts) usually have both upstream and downstream dependencies that usually change at a pace, which is different from these core components. To maintain both agility and reliability and enable loose coupling, it is important to integrate with a peripheral system in a manner that shields the core from everything else that surrounds it.

In this chapter, we will look at the LC application processing solution and examine the means by which we can integrate with other components in the ecosystem. You will learn how to recognize relationship patterns between components.

This chapter covers the following main topics:

  • Continuing our design journey
  • Bounded context relationships...