I think Docker was and still is a great way to popularize the concept of containers along with the smarter tooling around it, like resource schedulers. By the

I think Docker was and still is a great way to popularize the concept of containers along with the smarter tooling around it, like resource schedulers. By the time we adopted Docker (because it was popular and realized it's a good vehicle to push some concepts across organizations) we knew we're going to use it as a package system in a distributed scheduling environment (based on Mesos, Zookeeper, HDFS) and that it may get replaced later on. However, it took longer for Docker Inc. and the community to depart from the original ideas (initially very developer task centric, including trying to figure out how to store data inside containers) and figure how to enable scheduling, service discovery, health checking etc. I think Kubernetes did a good job popularizing better practices. IMO two of the few systems that were sound were Mesos and Kubernetes (and their roots are somehow interleaved) and neither puts the Docker as the central piece, nor the container, which is just a building block to achieve the actual goals of running distributed, highly available jobs and services efficiently in a shared environment.