Jupyter notebooks were fun to use for a bit, then I hit the inevitable wall of "ok, now let's turn this into a real, properly built script, but now everything is breaking for inexplicable reasons".
Notebooks are fine for early stage experimenting, but if you've got to the point where you start up you are relying on a notebook for anything, or your workflow consists of "start up notebook, run cells until I get to the one I'm working on" then you need to stop, and build it into something proper.
Experimentation is fine, but it should not come at the cost of writing things properly when the time comes, and they are not an excuse for not knowing some good software engineering. Serious alarm bells go off in my head when I read tweets like "Data science code doesn't need to follow the rules of good software engineering".
Edit: that remote notebook - is that honestly not one of the most terrifying things you've seen? That runs so counter to almost every good bit of software design and engineering practice about clarity, maintainability, good practice, security, etc that I can think of. It's the very definition of indecipherable, inscrutable hidden state and unknown side effects.