A system with thousands of event types

In the last 10 years we have applied event sourcing and CQRS in the development of our new ERP system. We now have almost two years of production experience. During these years we have run into interesting challenges that needed to be solved. In this session we share how we built a system with many thousands of event types, with the aim of serving thousands of companies and eventually millions of users.

Michiel Overeem is a Lead Software Architect at AFAS ( and part of the team that is responsible for their future ERP Cloud platform. He started with the development of the HTML5 frontend, but switched to the .NET backend. Now he is responsible for the CQRS and Event Sourcing implementation, as well as the deployment, management and monitoring services of the platform. Not only does he loves to write code, he also loves to read and write papers. That is why he started a PhD. As a PhD candidate with Utrecht University (as part of the AMUSE project (, he is also a researcher. The focus of his research is the upgrading of model-driven, cloud-based software.

picture of Michiel Overeem

Michiel Overeem

software development enthousiast