By advanced docker I mean especially the automatic deployments where CI builds the image, pushes it to a registry and then multiple instances around the world pick it up and update themselves either in AWS or any other service.

My main concerns are 1) I don't know any good article on the topic ("how-to", "why"), 2) It feels like more and more companies are targeting CI and code distribution (Render, Fly.io, Terraform (I guess)), 3) Docker is getting less "open" (https://news.ycombinator.com/item?id=17804916), 4) New alternatives are emerging (like nixos).