Phase 7 / 90 days

Move slow work out of the request path.

Add notifications and background workers after the learner has felt why slow side effects should not block user actions.

Teach queues with a real reason.

The first worker should exist because email, notifications, previews, or retries became awkward inside normal API handlers.

  • Notifications for replies and mentions.
  • Email notification jobs.
  • Go worker process that consumes queued jobs.
  • Retry behavior and failure recording.
  • Queues and workers.
  • Idempotency.
  • Retries and backoff.
  • Dead-letter queues.
  • Event-driven systems.

Expansion prompt

Add background jobs for notifications.
Keep the first queue simple.
Explain idempotency and retry behavior in beginner language.
Do not split the backend into microservices yet.
  • Notifications are created without slowing normal requests.
  • Failed jobs can retry and be inspected.
  • The learner knows why a queue is different from a function call.
  • The app still deploys in a simple low-cost way.