How would you answer an interview scenario involving Dockerfile best practices?

For an interview scenario involving Dockerfile best practices, I would first clarify the business goal, scale, constraints, and the failure or quality attribute the interviewer wants to explore. A Dockerfile describes the instructions used to build a Docker image. In this scenario, review a slow and insecure Dockerfile and explain which instructions you would change to reduce image size and improve security. I would then explain the main alternatives and tradeoffs, identify likely failure modes, and describe how I would validate the solution through testing, observability, security controls, and recovery or rollback planning.