Part 5/13:
On May 29, 2025, a new feature was added to the Service Control's binary responsible for additional quota and policy checks. This update was rolled out across different regions as part of a gradual deployment strategy. Crucially, the deployment incorporated a safety measure: a "red button" or kill switch designed to shut down problematic features instantly if needed.
However, despite careful planning, the update contained a critical flaw. On June 12th, an innocent-looking change to the policy data—seemingly benign but with missing or blank fields—was introduced into the regional policy tables. These tables are used by the service control to verify quotas and permissions.