What defines immutable infrastructure?

• A. Patch running servers in place
• B. Use ad-hoc deployments
• C. Replace rather than modify components; uses containerization and immutable artifacts
• D. Allow free-form changes to production

Answer: (C)

Immutable infrastructure means you don’t modify a component after it’s deployed. When a change is needed, you create a new version of the component (a new container image, a new VM snapshot, etc.) and replace the old one with that fresh artifact. This approach ensures every deployment comes from a known-good, versioned artifact, so environments stay consistent and reproducible. It also makes rollbacks simple—if the new version has issues, you redeploy the previous artifact. Containerization and immutable artifacts are natural partners here, since they encourage building, testing, and deploying an exact image and then swapping it in as a unit.

Patching running servers in place can lead to drift over time, where servers diverge from the intended configuration. Ad-hoc deployments and free-form changes in production undermine reproducibility and make it hard to audit or rollback.