What is Event Sourcing?

Event sourcing is a software architectural pattern that involves storing a log of events that describe changes to the state of an application. This log of events is called the event store.

The event store is a central repository that stores all the events that have occurred within the system. Each event represents a change to the state of the system, such as the creation of a new customer record or the modification of an existing record.

The key principle of event sourcing is that all changes to the state of the system are recorded as a series of events. These events are stored in the event store and can be used to reconstruct the current state of the system at any point in time.

One of the main benefits of event sourcing is that it allows the system to be easily rebuilt or reconstructed from the events stored in the event store. This can be useful in situations where it is necessary to recover from a system failure or to track the history of changes made to the system.

Event sourcing can also be used to facilitate collaboration between multiple users or systems by providing a clear record of the events that have occurred within the system.

Event sourcing is often used in conjunction with command and query responsibility segregation (CQRS) pattern, which involves separating the read and write operations of a system into separate components. This allows the system to scale more easily and to handle the increased load that can occur when multiple users are accessing the system simultaneously.