Starting in HS and continuing for years I developed the first and only complete software package I’ve ever made, for my father. He’s a EE and was doing a lot of his board design in excel — if I remember this meant he then needed to map the excel design onto a layout program to connect all the parts; the layout program generates a netlist and the netlist then goes to the actual layout person who figures out the final position of parts/traces on the board.
He hired me to make a VBA program that generates the netlist directly from excel. Refined it over the years and I believe he still uses it to this day. He can turn around a design in far keat time than it used to take.
I’m no EE — and it’s been probably 15 years since I’ve touched that code — so I may have gotten some details wrong here. But it was a cool project to work on and taught me a lot about code!