A deep dive into Cloudflare’s September 12, 2025 dashboard and API outage

This post details a significant outage caused by a bug in the dashboard leading to excessive calls to the Tenant Service API, which is critical for API request authorization. It highlights the impact on both the dashboard and other APIs, the response taken to mitigate the issue, and crucial lessons learned regarding release management (Argo Rollouts), 'thundering herd' problem mitigation, capacity planning for critical services, and the need for improved observability to differentiate between retries and new API requests.