Observability

Prometheus scrapes the API (queue depth) and each worker (throughput, latency, retries). Grafana ships with a starter dashboard in infra/grafana/.

Grafana (http://localhost:3002)Prometheus (http://localhost:9090)API metrics

In Docker Compose, Grafana is on port 3002 so it does not clash with Next.js on 3000. Default login: admin / admin.