Kubernetes v1.36 introduces a new alpha counter metric called route_controller_route_sync_total. This metric is part of the Cloud Controller Manager's route controller implementation. It increments every time routes are synchronized with the cloud provider. The metric's purpose is to help operators test the watch-based route reconciliation feature. This feature, introduced in v1.35, changes the route controller's behavior from a fixed interval to a watch-based approach. It reconciles routes only when node changes occur. This optimization reduces unnecessary API calls to infrastructure providers. Consequently, it lowers pressure on rate-limited APIs and improves quota efficiency. Operators can A/B test this by comparing the metric with the feature gate enabled versus disabled. In stable clusters with infrequent node changes, enabling the feature should lead to a significant decrease in sync operations. Feedback can be provided on Kubernetes Slack or GitHub. Further details are available in KEP-5237.