What is Event Sourcing?

Event sourcing is an approach for tracking changes to application state, stored as a sequence of events. Each change is associated with an event, which contains the timestamp and nature of the specific change. Instead of working with a sequence of static snapshots of our data, we use event sourcing to capture and store these events.

Using event sourcing when designing software puts a greater emphasis on how data evolves over time. It captures the journey, rather than just the destination. This allows systems based on event sourcing to have access to richer data that can be used for analytical purposes, but also to help develop new features. Event-sourced systems—and the developers who build them—are more capable of evolving rapidly to meet the changing needs of the business.