Anyone doing Gitops on IAC? Something like Crossplane and Argo/fluxCD? Has anyone done it on a production environment? How is the setup?do you have Crossplane in the platform cluster only or per every cluster? How do you manage stateful workloads....

Yes, we are. With Flux and Cluster API, not with Crossplane. When we tested it, it was not really ready (at least for our use case). See here for more info on how we have done it: https://traefik.io/blog/kubernetes-clusters-as-a-service-using-a-gitops-approach/

Thanks for sharing the blog @Michel Loiseleur very interesting read, worth checking crossplane again after next week the upbound provider have major fix for performance

Thanks @Michel Loiseleur