Three Patterns for 99.9% Reliability in Distributed Payments: Velocity-Aware Idempotency, Cross-Protocol Failover, and Shadow-Compare Migration. International Journal of Engineering Research and Science & Technology, [S. l.], v. 22, n. 3, p. 64–79, 2026. DOI: 10.62643/ijerst.2026.v22.n3.3800. Disponível em: https://ijerst.org/index.php/ijerst/article/view/3800. Acesso em: 7 jul. 2026.