Architecture notes — 2025

Internal writing, published here for candidates and partners who ask how things fit together.

Where we landed

Edge: Nginx terminates TLS and routes by hostname. api.acmepay.duckdns.org → API pods; www → the React build on object storage.
API: one FastAPI app today (acmepay/backend), being pulled apart into payments, payouts and reporting services.
Data: PostgreSQL 15 primary + read replica. Redis for idempotency keys and rate limits.
GraphQL: a thin read-only resolver over the same models, behind /graphql.
Runtime: Kubernetes in eu-west-1. Images built in CI, pushed to registry.acmepay.duckdns.org, deployed to acmepay-prod / acmepay-staging namespaces.

Production	`api.acmepay.duckdns.org`, `www.acmepay.duckdns.org`
Staging	`staging.acmepay.duckdns.org`, `staging-api.acmepay.duckdns.org` — same images, seeded data
Sandbox	`sandbox.acmepay.duckdns.org` — customer-facing test environment

Re-enable basic auth on staging after the load-test window.
Finish removing X-AcmePay-Key handling once v1 is gone.
Give staging its own certificate and stop serving it from the production edge under /staging/.
Decommission apigw.acmepay.duckdns.org and the old legacy.acmepay.duckdns.org dashboard host.