No nix is super cool! I really like the idea that guix and nix in having that system as code from build to deployment. I am not sure yet on how I feel about it for fleet/cluster deployments, k8s schedulers, network patterns like service meshes, ETCD, and operating on labels and cluster state are all super powerful.
I have looked too into using nix to make OCI containers and OCI containers to make flatpaks as well. All where they make sense of course.