for example, one notebook will be dedicated to explore columns, spot outliers and create transformations for specific column values.

This actually implies each notebook is a standalone "process", which makes a ton of sense. But this is where notebooks and proper SW design break, in traditional SW, the notebooks are actually python files, and then of course you can import one from another, unfortunately this does not work in notebooks...

If you are really keen on using notebooks I would just have a git repo with multiple files with functions you are using in the notebooks (like the transformation function etc) and use the notebooks for exploration only. where you import the python file from the notebooks with "import myfile"
Later you can build your pipeline from the logic you have in your various python script files. I hope this helps shed some light 🙂