Hey there, I know you meant something different, but I just wanted to chime in. At Ubicloud, we're building an open source cloud and our managed solution runs on Hetzner: https://www.ubicloud.com/docs
We're planning to tackle a managed k8s service next. If you have any feedback for our roadmap, could you drop us a line?
Our control plane is in Ruby, but our data plane uses different open source projects for managed services. For example, we use Linux KVM (C) and Cloud Hypervisor (Rust) for compute, SPDK (C) for block storage, Kubernetes (Go) well for Kubernetes.
My cofounder Daniel will talk about why we picked Ruby at the YC meetup next week. Maybe, we'll turn that into a blog post. Happy to hear your perspective as well!