Infrastructure code (IaC) has a problem that application code does not: changes outside of infrastructure code impact its ability to function as intended. I call this the shifting sand problem . The goal is for infrastructure code executions (of the same version) to always produce the same result. In this sense, we want infrastructure code executions to be "repeatable" in the same way we strive to make application builds repeatable. When IaC executions aren't repeatable, unplanned work is the res...