preferences-event-sourcing

Event sourcing uses an immutable log of domain events to reconstruct state through event replay. This fundamental duality of events and state enables perfect auditability and temporal queries for aggregates like a financial ledger.

Event sourcing contrasts with CRUD persistence by appending immutable domain events rather than overwriting mutable state. This naturally enables CQRS, audit trails, and temporal queries within functional domain modeling.

Implement event sourcing for a user preferences aggregate by defining its commands, events, and state evolution logic. Apply the Decider pattern to map these elements to functional domain modeling principles for accurate state reconstruction.

The Decider pattern structures functional domain modeling by mapping commands to events and evolving state. Applying this pattern to event sourcing facilitates clean state reconstruction and explicitly supports CQRS architecture.

EventStorming facilitates event discovery by collaboratively mapping domain events before implementation. It directly connects discovered events to functional domain modeling principles, establishing the immutable log required for state reconstruction.

Hoffman's ten laws of event sourcing provide a strict framework for implementing event replay, state reconstruction, and CQRS. These laws contrast with CRUD persistence and guide the application of functional domain modeling principles.