Technical Due Diligence: What PE Firms Actually Look For

Founders prepare for technical due diligence like it's a code review. It isn't. The diligence team isn't grading your architecture for elegance. They're hunting for risk that changes the price.

That distinction matters because it changes what you fix. You can walk into diligence with average code and clean operations and do fine. You can walk in with brilliant code and one irreplaceable developer and watch seven figures come off the valuation.

I've sat on the buyer's side of these reviews. Here's what actually gets flagged.

The List That Moves the Price

Key-person risk. One developer who holds everything in their head is the single most common finding, and the most feared. If your lead engineer quitting would stall the product for six months, the buyer prices that in. They'll model it as risk, and risk always costs the seller. Every critical system needs at least two people who can run it and documentation that would let a third learn it.

Undocumented systems. When the diligence team asks how the platform works and the answer is a two-hour verbal walkthrough from your CTO, that's a finding. Undocumented systems read as unmaintainable systems, whether or not that's true. Buyers assume the worst because they have to.

Security gaps. Shared admin passwords. Former employees with live access. No audit trail, no incident plan, customer data sitting unencrypted. None of this needs to be exotic to kill momentum. A basic security failure discovered in diligence doesn't just cut price. It can add escrow holdbacks, remediation conditions, and months of delay.

Licensing surprises. Open-source components with viral licenses baked into your commercial product. Seat counts that don't match your contracts. A "we've always done it that way" integration that violates a vendor's terms. Licensing problems are cheap to find and brutal to discover late, because they raise a worse question: what else didn't you know about your own product?

Cloud spend nobody can explain. Buyers read your infrastructure bill as a proxy for operational discipline. If your cloud costs grew 40% and nobody can say why, the buyer sees a team that isn't watching the store. Unexplained spend also flows straight into the margin math, and margin math is the valuation.

AI features that are demos wearing a suit. This one's new and it's everywhere. Companies bolt a thin AI feature onto the product, put it in the sales deck, and price the company like an AI business. Diligence teams have learned to pull the thread: is this a real capability with usage data and retention behind it, or a wrapper around someone else's API that three customers have touched? If your AI story inflates the multiple, expect it to get stress-tested hard. A demo priced as a product is the fastest valuation haircut in the room.

Why Buyers Flag It Even When It's Fine

Founders push back on findings all the time. "That system's stable, it hasn't gone down in years." Doesn't matter.

Diligence isn't about how things run today under the people who built them. It's about what happens under new ownership, new pressure, and possibly new staff. The buyer isn't buying your Tuesday. They're buying your worst week two years from now.

So anything opaque gets treated as fragile. Anything undocumented gets treated as unknown. Anything unknown gets priced as risk. That's not the buyer being unfair. That's the buyer doing their job.

The Math on Fixing It Early

Here's the thesis, and I'll state it plainly: every item on that list is fixable before diligence starts, and fixing it costs a fraction of what the finding costs you.

Run your own numbers. Documenting your core systems and cross-training a second engineer is weeks of focused work. Cleaning up access controls and licensing is a project measured in thousands of dollars. Compare that against a buyer trimming even a single turn off your multiple, or parking part of the purchase price in escrow against remediation you'll pay for anyway.

You'll fix these problems either way. The only question is whether you fix them on your timeline at cost, or on the buyer's timeline at a discount to your valuation.

The same logic applies to PE operating partners post-close. Every finding you didn't force before the deal becomes your integration problem after it. A pre-LOI technical review on your own portfolio targets is the cheapest insurance in the deal.

Run Your Own Diligence First

The move is simple: put your company through diligence before the buyer does. Same checklist, same skepticism, twelve months earlier. Find the key-person risk, the undocumented systems, the security gaps, the licensing exposure, the mystery spend, and the AI theater while they're still cheap to fix.

That's work we do inside fractional technology leadership engagements, including due diligence support for founders heading into a process and PE firms evaluating targets.

The buyer's team will find it. The only decision you control is whether they find a problem or a fix.