Event Sourcing is a method of capturing all changes to the state of an application as a sequence of events. Instead of storing just the current state, every change is recorded as an immutable event, which can be replayed to reconstruct past states or derive new information. This approach is useful for maintaining a clear audit trail, enabling system scalability, and supporting complex business logic by reconstructing states at any point in time.
In the "methods-and-patterns" quadrant, Event Sourcing offers a strategic approach to handling state management and data consistency across distributed systems. It is especially relevant in the "assess" ring as organizations explore its potential benefits and challenges before full adoption. Its application can lead to improved traceability, easier debugging, and better alignment with domain-driven design principles. However, like any architectural choice, it comes with trade-offs, such as increased complexity in data management and potential challenges in system performance.