Kubernetes Operator with Kubebuilder: best practices to avoid conflicts, unnecessary retries, and endless reconciliations

The article explains how to design Kubernetes Operators with Kubebuilder to handle update conflicts when multiple controllers act on the same Custom Resource.

It clarifies the difference between generation, which tracks spec changes, and resourceVersion, which identifies the live object revision.

Concurrent updates can trigger 409 Conflict errors, so separating spec and status and using the status subresource is recommended.

A robust reconciler should explicitly handle conflicts, reread the object, and retry only the necessary operations.

Avoiding endless reconciliation loops caused by repeated updates improves Operator reliability and scalability.