So I built one of these. Two years as the founder, the only engineer, and the guy who ran it. Wrote every line, handled every fire. And the stuff that could've sunk a buyer wasn't in the code. It was everything holding the company together that lived nowhere but in my head and my personal accounts. That's the part you can't see in a demo. So here it is, from someone who was the load-bearing wall. The rules that weren't written down. The system depended on things like "the monthly number is the truth, never rebuild it from daily data." Looked like a quirk. Was actually load-bearing. A new engineer "cleans that up" and doesn't find out for weeks he broke billing. That knowledge was in my head, not the code. The manual work nobody counted. My commit history has the same cleanup done by hand thirteen times. Every one was me looking at bad data and deciding what to kill. That judgment isn't in the software. It walks out when the founder does, and suddenly the "automated" system needs a human it doesn't have. The single points of failure that were actual people. For a long stretch, one person could move money out of the operating account. One. Every payment a manual request to that person. No backup. Not on any org chart — just true until the day it isn't. Whose name is production actually under? This is the one I'd check first. The database, the vendor logins, the domain, the deploy accounts — company entity, or the founder's personal Gmail? Because if production runs on one guy's personal logins, you're not buying infrastructure. You're buying a promise he'll hand it over later. That transfer is real work, and closing the deal doesn't do it. None of it shows in a demo. Product works, dashboards green, founder standing right there being helpful — and quietly being the thing the whole company leans on. I learned all of this the expensive way. If you're buying a founder-run company, or you don't want to inherit a mess you couldn't see, that's the question: how are you finding the invisible line items? Because "the founder absorbs it" is the biggest line on every small-company balance sheet, and it disappears the day you close. If you're under LOI on something and want another set of eyes on exactly that — the tribal knowledge, the key-person stuff, whose accounts hold what — hit me up. I'll do a first pass free and tell you where I'd dig. It's what I do now, and I'd rather be useful than sell you anything. What's the worst "it was all in the founder's head" thing you've hit after closing? Genuinely want to hear it.