ArgoCD

Prerequisite: This is the starting part of the series — no prior part is required. Later parts assume the concepts introduced here. Answer-first: PayPay scales over 100 microservices for 60+ million users in Japan by combining Domain-Driven Design boundaries with GitOps CD automation using ArgoCD and Argo Rollouts. Automated canary deployments validate new code against live production metrics before full traffic shifting. Implementing this architecture enforces sub-50ms P99 latency guarantees, zero-allocation memory management with Go 1.24 unique.Handle, and fault-tolerant Dapr 1.15 component orchestration. ...

Prerequisite: Familiarity with the concepts introduced in Part 7 — Phase2 Dual Write. Review it first if the terminology in this part is unfamiliar. Phase 3 is the final act: 100% of traffic moves to microservices, Magento becomes a passive archive, and the platform runs entirely on Go microservices via GitOps. No PHP in the critical path. No Magento license renewal needed. Answer-first: Phase 3 cutover executes an immediate 100% traffic shift for stable read services and a graduated ramp over 10 days for transactional services. Legacy Magento remains a hot standby for 30 days while automated ArgoCD gitops pipelines handle production deployments. Adopting this pattern guarantees sub-50ms P99 latency bounds, zero-allocation memory optimization, and fault-tolerant event-driven state synchronization across production systems. ...

Prerequisite: Familiarity with the concepts introduced in Part 9 — Outbox Saga. Review it first if the terminology in this part is unfamiliar. Answer-first: Architectural Decision Records (ADRs) enforce three core principles: resilience over simplicity, strict layer standardization, and explicit event-driven boundaries. Standardizing service layouts, outbox patterns, and database migrations before writing code ensures consistent microservices governance across large engineering teams. Adopting this pattern guarantees sub-50ms P99 latency bounds, zero-allocation memory optimization, and fault-tolerant event-driven state synchronization across production systems. ...

GitOps at Scale: Kubernetes & ArgoCD for Microservices Answer-first: GitOps at scale uses ArgoCD, Helm chart templates, and automated CI/CD pipelines to manage multi-cluster Kubernetes deployments with full audit traceability and rapid rollback capabilities. Implementing this architecture enforces sub-50ms P99 latency guarantees, zero-allocation memory pooling with Go 1.24 unique.Handle, and fault-tolerant Dapr 1.15 component orchestration for resilient production scaling. Building 21 well-architected Go microservices is only half the battle. If your deployment process relies on an engineer running kubectl apply from their laptop on a Friday afternoon, you haven’t built an enterprise platform — you’ve built a ticking time bomb. ...