What is Infrastructure as Code and why do teams use it instead of the cloud console?

What the interviewer wants to hear

• Infrastructure is defined in versioned files and created by a tool
• Repeatable, consistent environments for dev, staging and prod
• Changes are reviewed through pull requests and plans
• Easier recovery and audit history from version control
• Declarative tools like Terraform or OpenTofu track state

Model answer

Infrastructure as Code means describing networks, servers, databases and permissions in text files, then letting a tool such as Terraform, OpenTofu or CloudFormation create and update them. The files live in version control, so every change has an author, a review and a history. Teams use it because it makes environments repeatable: dev, staging and prod come from the same modules with different variables, so they do not drift apart. A plan step shows exactly what will change before anything happens, which makes reviews safer than clicking in a console. It also speeds up recovery, because you can rebuild an environment from code after a disaster. Declarative tools keep state and compare it with the real world, so they can detect drift when someone does make a manual change.

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