"This is not just another technical book—it’s a roadmap to more predictable, maintainable, and successful software projects. Martin Dilger has created an invaluable resource that I believe will influence how we approach software development for years to come." - Gabriel. N. Schenker

"By reading this book, you won’t just learn new techniques — you’ll transform the way you approach software development. You’ll gain clear, actionable steps to solve problems, communicate with unprecedented clarity, and estimate projects more accurately. In essence, you’ll be equipped to dismantle complexity and foster collaboration like never before." - Adam Dymitruk

"Focusing on a practical implementaion really worked for me. I appreciate the work you have done here." - Gary Craine

"Highly recommended reading" - Michael Plagge

"Thanks for writing the book, it will save me so much time and toil. I really like the Todo pattern to simplify the Saga. Also using an aggregate for uniqueness check is very nice." - William Power

"The book is packed with knowledge and provides concrete example implementations. It advances the entire topic and makes it easier for developers to access. I can only recommend it." - Sebastian Bortz

Before you buy the print edition - new chapters are constantly added to the Leanpub Version. If you want access to these new chapters, please consider to buy the book on Leanpub.

This book gives a practical introduction to eventmodeling and eventsourcing with a focus on how to implement eventsourced systems in practice.

Unlike other books covering the topic, we will really dive into the code and build a softwaresystem basically from idea to running software using state of the art development practices.

In Part I, we´ll cover the foundations of distributed systems. You will learn about CQRS, Eventsourcing and the fundamentals that took me 15 years to learn.

Part II focuses on the modelling part - I will show you how I model information systems using Eventmodeling in a practical way.

Part III really goes into the code - finally showing how an eventsourcing system is implemented.

Part IV builds a comprehensive Pattern Catalog and gives you quick guidance no how to implement typical scenarios in eventsourced systems.