Event Sourcing over CRUD for Audit Trails

The team decided to replace standard CRUD in PostgreSQL with Event Sourcing for financial transaction audit trails. Motivation: CRUD overwrites previous states, losing business context needed for compliance. The chosen approach stores immutable domain events in Kafka, with materialized views in Postgres for reads. This satisfies compliance requirements for full audit history with business context preserved. Reference architecture: Martin Fowler's Event Sourcing Pattern article. Implementation: event producers in src/services/transactionService.ts and consumer/store logic in src/events/eventStore.ts.