Posts by: Yvonne Ceelie

In one of my previous blogs, I wrote about using Axon to cope with Set Based Consistency validation. It deals with the question: How can I validate a uniqueness constraint throughout the whole...

Introduction When using Axon Framework together with PostgreSQL, you will find out that PostgreSQL uses something that is called TOAST (The Oversized Attribute Storage Technique).

This blog is a how-to implement a Saga with Axon and Spring Boot. Saga’s are a powerful concept but, you need to think about other options before implementing a Saga. You’ll have to keep in mind that...

In message-driven systems, messages flow in many directions. This behavior helps to decouple applications to make these systems better scalable. When it comes to sensitive data, we need to know who...

Requests like “How do I ensure the email address in a User aggregate is unique?” or “How do I ensure usernames are only used once on command handling?” reach us quite often. We can rephrase them: How...