How would you answer an interview scenario involving Terraform modules?

In an interview, I would first define Terraform modules and the problem it solves, then explain how I would keep module responsibilities cohesive, expose only necessary inputs, validate variables, version shared modules, document upgrade expectations, and avoid hard-coding environment-specific values. I would also call out the main failure mode: creating one huge module for unrelated infrastructure makes changes risky and prevents teams from evolving components independently. Finally, I would describe how I would test, monitor, and safely roll back or recover the solution.