Over the last few years we have been building new systems that have event-sourced architectures. Event-sourcing is a good fit for our needs because the organisation wants to preserve an accurate history of information managed by the system and analyse it for (among other things) fraud detection. When we started, however, none of us had built a system with an event-sourced architecture before. Despite reading plenty of advice on what to do and what to avoid, and experience reports from other projects, we made some significant mistakes in our design. This talk describes where we went wrong, in the hope that others can learn from our failures.
But it’s not all bad news. We were able to recover from our mistakes with an ease that surprised us. I’ll also describe the factors that allowed us to easily change our architecture, in the hope that others can learn from our successes too.
Presented at DDDEU 2020.