Infrastructure as code
Describing servers, databases, and networks in files a program applies, in place of clicking through a cloud console.
What it tells you about a developer
IaC experience means someone treats infrastructure with the same discipline as application code: reviewed, versioned, reproducible. It marks the developers a company trusts with its whole cloud footprint rather than one console screen. On GitHub the tell is repositories of Terraform or CloudFormation files.
Infrastructure as code stores a system's whole setup as text files in a repository. Running a tool like Terraform reads the files and creates or updates the real cloud resources to match. The setup becomes reviewable, repeatable, and recoverable: a fresh copy of the whole environment can come up from the files alone. It is a core practice of DevOps.