No matter how you like to participate in developer communities, Pulumi wants to meet you there. If you want to meet other Pulumi users to share use-cases and best practices, contribute code or documentation, see us at an event, or just tell a story about something cool you did with Pulumi, you are part of our community.

Pulumi Community

Is it possible to annotate an existing k8s namespace ("kube-system") with pulumi?

I don't believe so. We're working resource "adoption" so you could pull existing resources into your Pulumi app to manage them, but it's not yet available.