at what headcount did tracking your people stop fitting in a spreadsheet?

we're a bit over 50 now and i'm the one who ended up owning all the people admin, mostly by accident.

time off is a spreadsheet. signed documents sit in a folder. whether someone actually finished onboarding is something i know because i remember it, not because it's written down anywhere.

none of that has broken yet. it's just starting to feel like the kind of setup that works right up until the day it really doesn't, which i assume is the week somebody leaves and i need their paperwork in a hurry.

for anyone who's been through this, when did you stop improvising? was there a specific thing that forced it, or did you just decide one day that was enough.