Did you ever wonder how to actually switch the model from the CRUD one to EventSourcing? There’s one thing you should consider. The initial event that has to be published for existing data. Also called the opening balance.

At some point, one will reach a moment when they’re able to switch from the old model to the new one. Well crafted, event sourced aggregate. With 100% mutant coverage.

But then the questions pop up… How do you migrate data from legacy model to the new aggregate? How should you seed the aggregate with initial event?

https://blog.arkency.com/the-final-trick-when-moving-from-crud-to-event-sourcing/