How does Rails handle large-scale event sourcing with immutable event stores?

Rails implements event sourcing by persisting immutable domain events and rebuilding state from event streams.

Event sourcing replaces traditional state storage with a sequence of immutable events that represent every state change. In Rails, this is typically implemented using an event store table or external systems like Kafka or EventStoreDB. The current state of an entity is derived by replaying events. This provides auditability, temporal queries, and easy rollback. However, it introduces complexity in rebuilding projections and managing schema evolution of events.