https://github.com/githubsaturn/captainduckduck
It made it so much easier to deploy new changes (just `captainduckduck deploy` and done). We also use minio.io (open-source S3) and are extremely productive with those tools.
It's perfect for web agencies. It's not sophisticated enough for k8s' use case, but it's extremely easy to use (you can just add nodes and it will restart containers automatically [1]).
[1]: https://captainduckduck.com/docs/app-scaling-and-cluster.htm...