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)
1
Part 1: Foundations
4
Part 2: Real-World DDD
12
Part 3: Evolution Patterns

EventStorming

“The amount of energy necessary to refute bullshit is an order of magnitude bigger than to produce it.”

– Alberto Brandolini

Introducing EventStorming

In the previous section, we gained a high-level understanding of the LC issuance process. To be able to build a real-world application, it helps to use a method that delves into the next level of detail. EventStorming, originally conceived by Alberto Brandolini, is one such method for the collaborative exploration of complex domains.

In this method, you simply start by listing all the events that are significant to a business domain in roughly chronological order on a wall or whiteboard, using a bunch of colored sticky notes. Each of the note types (denoted by different colors) serves a specific purpose, as outlined here:

  • Domain event: An event that is significant to the business process – expressed in the past tense.
  • Command: An action or an activity that may result in...