Monthly Meetup - March 2017

Public group


Arthur van Schendelstraat 500 · Utrecht

How to find us

Infi is walking distance of Utrecht Vaartsche Rijn train station or one bus stop away from Utrecht Centraal Station. Refer to 9292ov for more details. If you're travelling by car, there's paid parking in the surrounding neighborhood.

Location image of event venue


"Event sourcing is easy!" they said. "Just record all of your user events" they said. "They're always useful." they said. So you did. You kept all the events. All of them. And now that you have them, there's just one question on your mind: How the heck do I manage all of it?!

Fear not. This month, two speakers we have. Powerful event wizards they are. Speak about the Dark Side of Event Sourcing they will. Remember: Collection leads to storage. Storage leads to maintenance. Maintenance leads to legacy. Legacy...leads to suffering.

*ahem* With food, drinks and space from the excellent folks at Infi, it's going to be one heck of an evening!

19:00 - Doors open
19:30 - Welcome
19:35 - Main Talk: The Dark Side of Event Sourcing
20:20 - Raffle & News
20:25 - Social!

Main Talk: The Dark Side of Event Sourcing: Managing Data Conversion
Evolving software systems often includes data schema changes, and those cause the need for data conversion. This is no different in event sourced systems. Converting data between schemas while continuing the operation of the system is a challenge. In this talk, we will look at the possible conversion operations, the techniques to execute them, and strategies for deployment with zero-downtime. We will look at the possibilities and the trade-offs for designing and implementing upgrades for event sourced systems.

Speaker: Marten Spoor (@martenspoor (
Marten is a Software Architect at AFAS ( ) and part of the team that is responsible for their future ERP Cloud platform. He finished his master in Business Informatics at the Utrecht University in 2016, (as part of the AMUSE project - ) and graduated on the topic of event sourcing data conversion.

Speaker: Michiel Overeem (@michielovereem (
Michiel 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 researches the upgrading of model-driven, cloud-based software.