26 App Services. Zero Health Checks. In a Bank. Processing Transactions.

Twenty-six Azure App Services. Not one had a health check endpoint configured. In a bank. Processing transactions. Serving customers. The platform just assumed everything was healthy. Hope is not a strategy. Without health checks you get zombie instances. The process is running, the instance is up, but the application inside is dead. The load balancer keeps sending traffic to it. Users get errors. Nobody knows why until someone manually checks. In a banking environment where every failed request could be a failed transaction. The rollout was done in 5 rounds - not a big bang. Round 1 covered non-critical, low-traffic services to validate the pattern. Then internal APIs, mid-tier services, customer-facing applications, and finally the critical banking workloads. Every round through CAB with full rollback documented before touching anything. The implementation: Azure Policy to enforce health check configuration. Actual policy -- not a best practice document nobody reads. If you deploy an App Service without a health check, the deployment gets flagged. Automatic unhealthy instance replacement kicks in the moment a probe fails. The team finds out from the system, not from a…