I use docker extensively with python backed ansible scripts to manage my product deployments (with a jenkins CI/CD pipeline). That has been a lot of fun, but I have also played with both Kubernetes and Openshift.
I love what Openshift Origin can do, but the learning curve is like a brick wall (See Dwarf Fortress Fun for an example) and the costs are far from minimal.
Kubernetes is easier to learn, but comes with its own gotchas.
What do you do to maintain stable deployments that allow for easy CI/CD? How do you minimize costs with your solution?
There's a learning curve, and new features are being added, but at this point I would not hesitate to recommend Kubernetes to just about anyone.
CI: We standardize on CircleCI and it gets the job done, but has some serious shortcomings. I've also come close to building my own on top of the k8s cluster and it's not the correct time investment for me right now, but I'd consider building my own in the future. I've yet to find a CI framework I really like.