OCI Retail Platform architecture combines Kubernetes on Ubuntu nodes with PostgreSQL 16 for a scalable e-commerce backend, fronted by Cloudflare WAF and OCI Load Balancer with NGINX Ingress Controller for TLS termination. Traffic flows from retail stores through Cloudflare to the public DMZ subnet, then to a private Kubernetes cluster running Next.js store frontend replicas and microservices APIs, all persisting data to an isolated PostgreSQL database subnet. Prometheus and Grafana monitor application and database metrics, with Alertmanager routing incidents to Microsoft Teams or Slack, while pgBackRest automates database backups to OCI Object Storage. This architecture demonstrates defense-in-depth security using VCN subnets, zero-trust ingress patterns, and observability-first operations for mission-critical retail workloads. Fork and customize this diagram on Diagrams.so to adapt the topology, add additional microservices, or integrate alternative OCI services like Autonomous Database. The three-subnet design isolates public, application, and database tiers, reducing blast radius and simplifying compliance audits for PCI-DSS retail environments.