This image shows a multi-tier topology consisting of a load balancer, a containerized application tier, and an autonomous database. All the resources in the topology are in a single availability domain and VCN in an Oracle Cloud Infrastructure region.

The load balancer is attached to a public subnet. An internet gateway allows traffic between the load balancer and users outside the cloud.

The application tier is in a private subnet. The application is composed of the following containerized microservices. The programming platform or language used to develop each microservice is indicated in parentheses.

Ingress (Nginx)
Router (Traefik)
Media (Node.js)
REST API (Node.js)
Storefront (HTML 5)
Tracking (Go)
Session DB (Redis)
Users (TypeScript)
Orders (Java)
Messaging (NATS)
Payments (Go)
Fulfillment (Micronaut)
Carts (Helidon)
Catalog (Go)

The autonomous database is in a private subnet.

A NAT gateway enables access from the private subnet of the application tier to the public internet.

A service gateway enables connectivity from the application tier to Oracle Cloud Infrastructure Object Storage.