I think he’s referring to the app being aware of static files so it can resolve their URLs, etc (without having to hardcode paths).

You develop by just assuming all your static files would be served by Django itself (and they will - using the dev server) and then change the project’s configuration to use a CDN or S3 (using a library - which will automatically collect & upload your files too) with no change to the underlying code.

I think they meant the Sprockets/Asset Pipeline or whatever the new Webpack-based solution is.

Asset Pipelining is a dingo plug-in, but a built in for Rails.