I used to work adjacent to product managers, know how all of that works, but, I'm not sure how to put it all together, and particularly, and the one person designing all of this.
Should I just create a set of Excel workbooks containing the different things that I need to do, for example, requirements, use cases, current issues, etc., and then write a script to turn everything in that spreadsheet into a set of JIRA tickets?
Staff engineers, principal engineers, founders, etc., how do you do it?
I would take a zero based budgeting approach first of all, list all the things. Then go through the list and I'm sure there's a decent percentage you were just doing out of habit and can immediately drop and forget about.
Then do another pass and figure out if there are things you are doing on a semi regular basis that aren't time sensitive but still 100% need to be done, chances are you can batch it and put it as a recurring slot in your calendar. Over time you might spot patterns where automation can help.
Then take the rest and if you're unsure if it's essential or not, you can chose to either ask someone (your boss) if it's important to them, or drop it on a trial basis to see if anyone screams.
You'll hopefully be left with a much smaller list and then you can start to think about the tooling and processes other folks are suggesting here.
In particular making big lists is a curse because they will never ever remain current, tend to grow much bigger and swallow time as you groom them in to other smaller lists you intend to do something with but find have suddenly become their own intractably large lists.
Much better to have a coarse plan and add detail as you get to it and be happy to delete things as well as add them. Then make sure you’re regularly revisiting the plan to make sure it still makes sense.
and github wiki for keeping notes as well...
and github code for scripts if some...