Welcome — let's get you started.

• Java 21 · Spring Boot 4.0.5 (Spring Framework 7, Jakarta EE 11) · Maven multi-module
• PostgreSQL 17 — schema-per-service in one DB (search_path = <service>, shared per connection)
• Liquibase migrations (manually wired — Spring Boot 4 ships no auto-config)
• Spring Data JDBC — chosen over JPA for explicit aggregate boundaries
• Kafka 4.1.2 (KRaft, single broker) — JSON wire format via Jackson 3
• Keycloak 26 + Spring Security — OIDC code flow for the ERP SPA
• Testcontainers for the integration-test seam
• React 18 + Vite + Tailwind v4 ERP SPA · TanStack Query for data fetching
• OpenTelemetry + LGTM — Prometheus · Tempo · Loki · Grafana, auto-instrumented (one correlated trace per Saga)
• Terraform IaC — single-AZ EC2 running the images via docker run, pushed to ECR

This is a hands-on demo — drive it yourself in the browser. Here's the quickest way in.

1. Click "Enter the ERP" below. You'll be sent to the Keycloak sign-in screen — the demo uses real login, not a bypass.
2. Sign in. Every persona's password is the same as its username. A friendly first login is sarah / sarah — a sales clerk who can place orders and watch them fulfil end-to-end.
3. Find the Demo Guide inside the app — the ? icon in the top bar — for the full cast (13 personas, each a different role) and ten step-by-step walkthroughs.
4. Switch persona whenever you like: sign out (top-right) and sign back in as someone else — the UI re-reads your role automatically.