Configuration Drift

Problem

DEV, TEST and PROD originally had identical infrastructure. Over six months people manually change settings. Now: DEV ≠ TEST ≠ PROD Deployments behave differently and nobody knows why.

Solution — Desired-State Configuration / IaC Reconciliation

Define the intended configuration and compare or reconcile environments against it.
Declared state
      ↕
Actual state
Unexpected differences become visible and correctable.
Core idea: configuration drift is the uncontrolled divergence between intended and actual system configuration.