How it starts
A manual step is added to a deployment because automating it would take a sprint that no one can prioritize. A reconciliation script is run by one person who knows the correct sequence of steps. An alerting threshold is set so high that it never fires, because the team is overwhelmed by false positives. A runbook describes a procedure that worked two versions ago. Each compromise is small. The total is an operating environment that depends on specific people remembering specific things.