> Are there any guides on best practices for bridging from notebooks to applications?

The main point of friction is that the "default" format for storing notebooks is not valid, human readable python code, but an unreadable json mess. The situation would be much better if a notebook was stored as a python file, with code cells verbatim, and markdown cells inside python comments with appropriate line breaking. That way, you could run and edit notebooks from outside the browser, and let git track them easily. Ah, what a nice world would that be.

But this is exactly the world we already live in, thanks to jupytext!