How would you answer an interview scenario involving CI/CD pipeline design?

In an interview, I would first define CI/CD pipeline design and the problem it solves, then explain how I would separate build from deployment, produce immutable artifacts once, run fast validation early, promote the same artifact across environments, protect production stages, and keep rollback procedures tested. I would also call out the main failure mode: rebuilding different artifacts for each environment or embedding manual undocumented steps makes releases difficult to reproduce and audit. Finally, I would describe how I would test, monitor, and safely roll back or recover the solution.