AKS Prepared Image Specification Is in Preview

This article reviews the Azure Kubernetes Service (AKS) Prepared Image Specification (PIS) now in preview. PIS allows you to pre-bake stable container images and host customizations into AKS-managed node images, avoiding image pulls at node boot and reducing scale-out latency. The author highlights benefits over DaemonSet/CronJob image-puller patterns, notes that PIS is a point-in-time snapshot requiring version updates, and shares performance gains (e.g., 74% median reduction for Windows bursts). They also warn about an undocumented RBAC requirement and a bug in the script generator, advising testing in non-production environments due to preview status.