[primarydonkey]

I used this and can recommend it, since it also shows you the outputs of different versions.

But as another commenter said, when I got to the point of needing to diff my notebooks, I realized that I could move some of the code into separate python files.

If you're a business analyst, one use case is if you need to process some data e.g. every quarter, but the data changes a bit every time so you need to update the approach slightly (e.g. data structure changes, new mapping rules). With nbdiff it's easy to keep track of changes while having some helpful visualizations in the same file.