Transactional Outbox

Previous Chapter: Part 1 — Microservices & GitOps Blueprint | Series Hub | Next Chapter: Part 3 — Data Infrastructure: From Aurora to TiDB Answer-first: PayPay guarantees zero event loss and strict ledger decoupling under promotional surges exceeding 1,250 TPS by combining the Transactional Outbox pattern with Debezium CDC and Apache Kafka. Consumer groups utilize the CooperativeStickyAssignor to prevent rebalance stop-the-world pauses, while a two-stage Redis distributed lock provides exactly-once processing semantics before persisting updates into the database. ...

← Previous Chapter: Part 8: Phase 3 — Full Cutover Zero Downtime | Series Hub | Next Chapter: Part 10: 24 Architecture Decisions (ADRs) → Answer-first: Handle distributed transactions when a customer places an order by combining the Transactional Outbox pattern in PostgreSQL with Saga Choreography over Dapr Pub/Sub, guaranteeing eventual consistency across Cart, Order, Payment, and Fulfillment. When a customer hits the order button on the Composable Commerce platform, up to 7 events must fire in sequence across 4 fully independent services: Order created → Payment authorized → Stock reserved → Fulfillment triggered → Notification sent → Loyalty points awarded → Shipping label generated. Any single link in this chain can snap. The network can drop. The database can crash. A third-party payment gateway can time out. ...

Banking Microservices in Go: Saga & Event Sourcing Answer-First: Banking microservices architecture in Go enforces strict bounded context isolation, double-entry immutable ledgers, and distributed Saga orchestration to guarantee zero financial data loss. By combining optimistic concurrency control, transactional outbox event streams, and SPIFFE/SPIRE zero-trust mutual TLS, financial platforms process over 10,000 TPS while maintaining sub-10ms latency and strict PCI-DSS v4.0 regulatory compliance. Prerequisite: Readers should possess solid foundations in relational database transactions (ACID, isolation levels, row locks), distributed systems primitives (Saga patterns, outbox pattern, idempotency keys), and Go concurrency patterns (goroutines, contexts, connection pooling). ...