Global Payment Gateway

Internal systems do not become correct at the API boundary; they become correct through reconciliation with external truth.

Balance is a lie; the journal is the truth. Explore how to architect a high-throughput ledger that preserves financial correctness under extreme concurrency.

Why Two-Phase Commit (2PC) fails at scale, and how to architect the Saga Pattern and Transactional Outbox to guarantee data consistency across microservices.

Exactly-once delivery is an illusion in distributed networks. In this post, we architect an Idempotent Payment API to guarantee financial correctness amidst network timeouts, race conditions, and retry storms.