I manage a mid-size fleet of EC2s across 4 AWS regions with several auto scaling groups per region. The VMs themselves are general purpose and the image is buil

I manage a mid-size fleet of EC2s across 4 AWS regions with several auto scaling groups per region. The VMs themselves are general purpose and the image is built with our standard set of dependencies. All of our applications are homogeneous as far as stack, so the process for managing the VM ecosystem is pretty simple. The various application binaries are deployed through a small set of SSM documents (with an automation layer built on Jenkins in front and using S3 to shuffle things around). The design predates me, but I've made small improvements to it. It works fine and its cheap as far as AWS stuff goes. We are slowly migrating applications to ECS Fargate which I have yet to form a strong opinion on. Docker is a nice experience even if the leanest artifacts are still chunkier than a naked application. For reference, I have built some larger and some smaller stuff using k8s and even docker+machine once. May not be at the scale you are thinking, but it serves maybe 100k users spread across 10k customers working in 30 something countries.