event-sourcing
Installation
SKILL.md
Event Sourcing
Core Concepts
Event Sourcing stores state as a sequence of immutable events, rather than current state. The current state is derived by replaying events.
Traditional: SAVE current state → DB (overwrites)
Event Source: APPEND events → Event Store → REPLAY to rebuild state
Key principles:
- Events are immutable — never update or delete them
- Events are facts: "OrderPlaced", "ItemAdded", "PaymentProcessed"
- State is derived from event history
- Full audit trail is free — the events ARE the history