I am building Clace https://github.com/claceio/clace, an app server for containerized applications. The goal is to build something like Nginx Unit, but supporting any language/framework. Each app runs in a separate container. App updates are done using a blue-green staged deployment.

Clace already supports most python based apps (wsgi or asgi), any other language works with a custom Dockerfile. Plan to add support for automatically shutting down idle containers, allowing for scaling down to zero for each app.