- Graduated seccomp profile defaulting to GA.
  
  Set the kubelet `--seccomp-default` flag or `seccompDefault` kubelet configuration field to `true` to make pods on that node default to using the `RuntimeDefault` seccomp profile.
  

- Promote SupportNodePidsLimit to GA to provide node-to-pod PID isolation.
  Promote SupportPodPidsLimit to GA to provide the ability to limit PIDs per pod. ([#94140](https://github.com/kubernetes/kubernetes/pull/94140), [@derekwaynecarr](https://github.com/derekwaynecarr))

- Promote Cronjobs storage version to `batch/v1`. ([#102363](https://github.com/kubernetes/kubernetes/pull/102363), [@mengjiao-liu](https://github.com/mengjiao-liu))
- Promote `CronJobControllerV2` flag to GA, with removal in 1.23. ([#102529](https://github.com/kubernetes/kubernetes/pull/102529), [@soltysh](https://github.com/soltysh))

- ValidatingAdmissionPolicy now exclude TokenReview, SelfSubjectReview, LocalSubjectAccessReview, and SubjectAccessReview...

- Introduce a method 'GetPCIeRootAttributeByPCIBusID(pciBusID)' for third-party DRA drivers to provide common logic for the standardized device attribute 'resource.kubernetes.io/pcieRoot' ([#132296](https://github.com/kubernetes/kubernetes/pull/132296), [@everpeace](https://github.com/everpeace)) [SIG Node]

## Major themes

Kubernetes is developed by community members whose work is organized into
[Special Interest Groups](https://github.com/kubernetes/community/blob/master/sig-list.md), which provide the themes that guide their work. For the 1.9 release, these themes included:

### API Machinery

- Promote JobSuccessPolicy E2E to Conformance ([#130658](https://github.com/kubernetes/kubernetes/pull/130658), [@tenzen-y](https://github.com/tenzen-y)) [SIG API Machinery, Apps, Architecture and Testing]

- Promote NodeLease feature to GA.

    * sync time.
 
    * The goal is for administrators to be able to alert on proxies that, for
    * whatever reason, are quite stale.

- Windows Kubeproxy will use the update load balancer API for load balancer updates, instead...