Part 4: SRE Practices — Chaos Engineering with Chaos Mesh & Multi-Region Resilience

Previous Chapter: Part 3 — Data Infrastructure: From Aurora to TiDB | Series Hub | Next Chapter: Part 5 — Campaign Architecture: Surviving the 10-Billion Yen Surge Answer-first: PayPay sustains 99.999% payment availability by embedding Chaos Mesh fault injection directly into production pipelines, proactively testing pod kills, network partitions, and clock skews without impacting consumers. Paired with strict SLO/SLI error budgets, gRPC deadline propagation, and adaptive concurrency limits, the infrastructure autonomously isolates degrading services and sheds load before cascading failures can propagate. ...

Part 8: QA & SDET Handbook: Testing Distributed Core Banking

Series Navigation: This is Part 8 (Final Chapter) of the Core Banking Systems Architecture Masterclass. ← Previous: Part 7 — Streaming Fraud Detection | Master Curriculum Hub | Curated Reading Map | Architecture Consulting Services Part 8: QA & SDET Handbook: Testing Distributed Core Banking Answer-first: Testing distributed core banking engines requires moving far beyond conventional mock-driven unit tests. By combining deterministic virtual-time concurrency testing with Go testing/synctest, automated ledger invariant property fuzzing, Jepsen split-brain chaos injection, and Envoy shadow traffic replay, financial SDETs mathematically guarantee strict linearizability, eliminate silent balance drift, and ensure continuous availability during catastrophic infrastructure network partitions. ...