Lesson 22 / 23
Monitoring & Rollback
Confirm every deploy is healthy with monitoring and health checks, and roll back fast to the last good artifact.
Watch the deploy, not just the pipeline
A green pipeline only proves the code built and passed tests — it says nothing about production. After deploy, watch error rates, latency, and key business metrics for a window before calling it 'done'.
Rollback strategies
When something breaks, the fastest fix is usually to roll back to the last known-good artifact — not to debug live in production. Blue-green makes this instant; rolling deployments roll the batches back the same gradual way.
Automate the trigger
Mature pipelines wire health checks and error-rate alerts to trigger an automatic rollback, instead of waiting for a human to notice and act at 2 a.m.
Final quiz 1 of 8
Final quiz
Quick check: What is continuous integration?
- Deploying once a year
- Manual testing only
- Merging often and verifying each change automatically
- Branching for months
Answer
Merging often and verifying each change automatically — Small frequent merges reduce conflicts.
Final quiz 2 of 8
Final quiz
Quick check: What separates continuous delivery from continuous deployment?
- Delivery has no tests
- Deployment skips builds
- They are identical
- A human approves the production release in delivery
Answer
A human approves the production release in delivery — Deployment releases every passing change automatically.
Final quiz 3 of 8
Final quiz
Quick check: Why build an artifact only once?
- So the exact tested output is what gets deployed
- To save disk space only
- To skip tests
- Because builds are random
Answer
So the exact tested output is what gets deployed — Rebuilding at each stage can change the result.
Final quiz 4 of 8
Final quiz
Quick check: Why pin a GitHub Action to a version tag or SHA?
- It runs faster
- A branch reference can change unexpectedly
- Branches are not allowed
- It hides logs
Answer
A branch reference can change unexpectedly — Pinning prevents surprise or malicious updates.
Final quiz 5 of 8
Final quiz
Quick check: Which checks should run first in a fail-fast pipeline?
- Production deploy
- Slow end-to-end tests
- Fast, cheap ones like linting and unit tests
- Manual sign-off
Answer
Fast, cheap ones like linting and unit tests — Cheap failures save time and money.
Final quiz 6 of 8
Final quiz
Quick check: Which strategy needs no duplicate full environment?
- Blue-green
- Both
- Neither
- Rolling deployment
Answer
Rolling deployment — Rolling replaces instances in batches.
Final quiz 7 of 8
Final quiz
Quick check: Where should CI secrets live?
- In the CI system's encrypted secret store
- In the repository code
- In README files
- In the build artifact
Answer
In the CI system's encrypted secret store — Never commit credentials to git.
Final quiz 8 of 8
Final quiz
Quick check: What should happen after a deploy?
- Nothing
- Monitor health and roll back if needed
- Delete logs
- Skip alerts
Answer
Monitor health and roll back if needed — A deploy is done when it is confirmed healthy.