Backend & systems·Resilience and failure handling
you trace the dependency graph and find one component whose failure takes everything else down with it.
Single point of failure
Also calledSPOF
A component with no redundancy whose loss causes total failure. They are easy to spot in the data plane and easy to miss in the control plane: the config service, the DNS zone, the single deploy pipeline, the one person with production access. Redundancy that shares a failure mode is not redundancy.