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"title": "Event Sourcing over CRUD for Audit Trails",
"content": "Decision: Move from standard CRUD in PostgreSQL to Event Sourcing with Kafka for audit trail of financial transactions.\n\nContext: Compliance needed full history of transaction state changes. Current CRUD overwrites previous states, losing history.\n\nAlternatives considered:\n1. Database triggers with history_logs table - Rejected because triggers only capture row changes without business context or user intent.\n2. Event Sourcing - Accepted. Stores immutable domain events (TransactionCreated, TransactionApproved, StatusUpdated) via Kafka with PostgreSQL materialized view for reads.\n\nImplementation:\n- Event producers: src/services/transactionService.ts\n- Consumer/store: src/events/eventStore.ts\n- Reference: Martin Fowler's Event Sourcing Pattern article\n\nRationale: Satisfies compliance audit requirements while preserving business context and user intent.",
"summary": "Adopted Event Sourcing with Kafka and PostgreSQL materialized views over CRUD for financial transaction audit trails.",
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