Programming

I wrote some VBA for a job a long time ago. It was pretty good for making quick and dirty UI in Excel -- like, click a cell and have it pop up a form you can interact with that will let you do data entry with less clicks/typing than whatever Excel would've made you do if you had to do it naively.

I used it for showing a list that could be filtered down by partially typing in text in one project. (A really basic autocomplete sort of thing, essentially.) For another project, I integrated IE and showed some complex data in the embedded browser with buttons (or maybe it was checkboxes? been too many years) in the form to quickly classify it and move on to the next entry without having to flip back and forth between multiple programs and manually open files. (Each entry corresponded to a row and widgets on the form updated values in various columns so I could go through all the data and fill out the full spreadsheet super fast.)

Alternatively, write a script that checks your spreadsheet for errors. e.g. add a reference to a regex library and use it verify that all the entries in a column match the data format you expect (like serial number patterns with hyphens in specific places).

You can also ask your coworkers for something tedious they have to do a lot in Excel and see if you can find a way to make it less tedious.