The Pocket Guide to building CQRS/Event Sourcing based applications using Axon
Minimum price
Suggested price

The Pocket Guide to building CQRS/Event Sourcing based applications using Axon

About the Book

The Command Query Responsibility Segregation Pattern is an architectural pattern to help build loosely couple, modular, scalable and event based applications. It advocates the usage of two separate models within an application - one model for processing operations that validate and change state i.e. Commands, the other model for processing operations that query state i.e. Queries. The Event Sourcing pattern advocates the building of applications as a System of Events rather than as a System of State.


Both are extremely powerful patterns but at the same time very complex to implement due to the inherent distributed nature of it. Applications wanting to adopt these pattern would need to implement various infrastructural aspects which this pattern requires thereby introducing a lot of accidental complexity. It is better off to utilize tools which provide a robust implementation of the CQRS pattern freeing developers to do what they know best - implement business logic.

This book does exactly that. Taking a real life application (Hotel Booking), we will build a complete CQRS and Event Sourcing based implementation utilizing the Axon Framework. Along the way, we will also see how to utilize supporting patterns such as Event Modeling / Domain Driven Design / Reactive Microservices. This book will also compare the approaches with other tools such as vLingo / Akka / Spring Boot and Event Store.

At the end of the book you will have a complete working knowledge of the fundamentals of the CQRS pattern and its applicability to real life projects

About the Authors

Vijay Nair
Vijay Nair

I am an event driven architectureal connoisseur and focus only on architectures centered around DDD / CQRS / Event Sourcing. I specialize in implementations around Axon / Eventuate and EventStore (Hey if you got a new event sourcing framework that I do not know please send it out to me - I act as a platform architect for my day job, an independent evangelist for DDD/CQRS/ES and also am an InfoQ editor for the architectural and design streams. I am also the author of the book - Practical Domain Driven Design with Enterprise Java (Apress)

Allard Buijze
Allard Buijze

Allard Buijze is software architect at Trifork, which delivers software development, consultancy and training services to both national and international organizations. As an architect, he is responsible for the technical choices in his projects and investigates technologies for their potential in the diversity of projects Trifork does. For the last decade, he has been developing and designing enterprise applications for both large-scale and smaller projects. His focus has always been on clean application design, maintainability and testing. The training of co-developers is a very important part thereof.

Allard has given several trainings in the areas of scalable architectures, test driven development, application design and clean coding. He strongly believes that good craftsmanship can only be achieved through continuous and intensive exchange of experience with others.

The last years, he has been investigating and applying CQRS to a number of projects. As a result, he created the Axon Framework, an open source Java framework that helps developers create scalable and extensible applications by providing the building blocks that CQRS based infrastructures typically require. Axon has a growing community and has already been successfully introduced in several projects around the world.

Table of Contents

  • Architectural Concepts

Authors have earned$9,883,643writing, publishing and selling on Leanpub, earning 80% royalties while saving up to 25 million pounds of CO2 and up to 46,000 trees.

Learn more about writing on Leanpub

The Leanpub 45-day 100% Happiness Guarantee

Within 45 days of purchase you can get a 100% refund on any Leanpub purchase, in two clicks.

See full terms

Free Updates. DRM Free.

If you buy a Leanpub book, you get free updates for as long as the author updates the book! Many authors use Leanpub to publish their books in-progress, while they are writing them. All readers get free updates, regardless of when they bought the book or how much they paid (including free).

Most Leanpub books are available in PDF (for computers), EPUB (for phones and tablets) and MOBI (for Kindle). The formats that a book includes are shown at the top right corner of this page.

Finally, Leanpub books don't have any DRM copy-protection nonsense, so you can easily read them on any supported device.

Learn more about Leanpub's ebook formats and where to read them

Write and Publish on Leanpub

You can use Leanpub to easily write, publish and sell in-progress and completed ebooks and online courses! Leanpub is a powerful platform for serious authors, combining a simple, elegant writing and publishing workflow with a store focused on selling in-progress ebooks. Leanpub is a magical typewriter for authors: just write in plain text, and to publish your ebook, just click a button. It really is that easy.

Learn more about writing on Leanpub