I just need to supply my bank statements to the accountant annualy (bank is TSB). They have a set of rules (less that 150 lines, not more than 3 months) that constrain how you can get the statements, and a 5-step process to open up the UI to download one, then select the dates, etc. You may imagine it's simply error-prone and repetitive.

A few years I didn't even need to change the script. But even when I needed it wasn't something too complex. As long as you constrain the expected behaviour and error early - it works perfectly well.