DDD Europe 2022 - Program

Implementing the Decider pattern


Jérémie Chassaing

Jérémie Chassaing

(This is a hands-on lab with limited capacity)

Transitioning to Event Sourcing looks like a leap of faith in the great unknown. But what if you could implement you model now and delay the decision of state or event storage ? The Decider pattern gives a well defined shape for Aggregates that is fit for Event Sourcing but works also with a classic Load from/Save to database persistence. This friction free shape let you start implementing your model on your current infrastructure, and move later, if needed to an event sourced persistence without any change to your domain model. No prior knowledge of Event Sourcing is needed. The hands-on will be in F# (using VSCode with ionide installed or Visual Studio with net6.0). We still will discuss how to implement the pattern in different languages.

About Jérémie Chassaing

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Jérémie Chassaing has been practicing Domain Driven Design and Continuous Improvement for 10 years as an architect at Availpro, a channel manager for independent hotels, to increase scalability and reliability to match its rapid growth. He's an active member of the F# community. You can also see his blog thinkbeforecoding, a blog dedicated to Domain Driven Design, CQRS and Event Sourcing.