Compliance & Audit Trail (Go, PostgreSQL, RabbitMQ, Vault, Elasticsearch, Prometheus) overview

An immutable audit trail system that captures, indexes, and monitors every compliance-relevant event across the organization. Go services ingest events from RabbitMQ queues and write append-only records to PostgreSQL with cryptographic hash chains for tamper evidence. Elasticsearch provides full-text search over millions of audit entries for investigator queries and regulatory reporting. HashiCorp Vault manages encryption keys and secrets for data-at-rest protection. Prometheus tracks ingestion lag, storage growth, and query latency. The tradeoff is storage cost growth over time and the difficulty of balancing retention policies with regulatory hold requirements.