Event Sourcing over CRUD for Financial Transaction Audit Trail

The team decided to replace standard CRUD with Event Sourcing for financial transactions audit trail. Problem: CRUD overwrites previous states, making compliance history queries impossible. Database triggers were considered but rejected because they lose business context. The chosen approach: store immutable domain events in Kafka, build materialized view in Postgres for reads. Files: src/services/transactionService.ts, src/events/eventStore.ts. Reference: Martin Fowler Event Sourcing Pattern article.