6.7Testing the Deployment Pipeline Itself

The deployment pipeline is software. It can have bugs. Test it.

What to verify:

• Rollback works correctly (trigger a rollback and verify the old version is restored)
• Health checks actually detect unhealthy instances (deploy a broken version and verify the pipeline stops)
• Smoke tests run against the correct environment (not accidentally testing staging when you think you are testing production)
• Notifications fire on failure (break the pipeline intentionally and verify Slack/email alerts)