Event Sourcing over CRUD for Audit Trail Compliance

The team decided to replace standard CRUD operations in PostgreSQL with Event Sourcing for the financial transactions audit trail. Motivation: compliance required the history of transaction #8821, but CRUD overwrites previous states and database triggers lose business context. Decision: use Kafka as immutable event log storing domain events, with materialized Postgres view for fast reads. Files: src/services/transactionService.ts, src/events/eventStore.ts. Reference: Martin Fowler Event Sourcing Pattern.