If you’ve ever bought a house, you know the drill: get an inspection before you close. A good inspector doesn’t just check that the lights turn on—they look inside the walls, test the roof, poke around the foundation. They’re hunting for, among other things, the stuff the seller should have attended to along the way but rather has let pile up.
Software due diligence works the same way. When you’re acquiring a technology company, the codebase is the asset. And like that house, it may look fine from the outside while harboring some expensive surprises. Software too often houses unaddressed problems: technical debt.
What is technical debt, really?
Technical debt is the accumulated cost of cutting corners during software development. Every time a team ships something fast instead of shipping it right—skips documentation, leaves security vulnerabilities unpatched, bolts on a workaround instead of fixing the root problem—they’re borrowing against the future. That debt compounds over time, just like financial debt.
In practice, technical debt shows up in a few distinct flavors. There’s code quality debt: messy, undocumented code that’s a nightmare to maintain or extend. There’s architectural debt: a system design that made sense when the company had ten customers but won’t scale to ten thousand. There’s open source license debt: snippets of GPL-licensed or even unlicensed code sitting in a commercial product, waiting to become a legal headache. There’s security debt: vulnerabilities that were flagged and never fixed. And there’s process debt: teams shipping without proper testing, review, or documentation practices in place.
Any of these, left unaddressed, can significantly erode the value of an acquisition—or create serious post-close problems for the acquirer.
Why it matters more in M&A
In normal business operations, technical debt accumulates slowly and companies have time to manage it. In M&A, you’re making a multi-million-dollar decision, often under time pressure, based on incomplete information. The target company has every incentive to present their technology favorably. Their developers have been heads-down building, not necessarily tidying up after themselves (or, worse, their coding assistants) along the way.
The risks are real and expensive. Significant code quality issues mean the acquiring engineering team could spend months just trying to understand what they inherited—and longer still to integrate it. Architectural problems can mean a product that simply can’t be scaled without refactoring. Open source license violations will need to be addressed before the product ships. And security vulnerabilities discovered post-close need remediation or risk breaches.
One thing we’ve seen repeatedly: acquirers who skip or rush the technical review tend to find out about these issues during integration, when it’s expensive and disruptive to address them. The companies that do it right identify the issues up front and either use them to negotiate better deal terms or make informed decisions about remediation costs and timelines before they sign.
What good technical due diligence looks like
A thorough software audit examines several dimensions. Code quality analysis looks at the structure, maintainability, and documentation of the codebase. Open source composition analysis (SCA) identifies all open source components in use, flags any with known security vulnerabilities, and reviews license obligations. Security assessment evaluates both the code itself and the processes used to build and deploy it. And a development process review examines how the team operates: their testing practices, their release cadence, their debt management habits.
The output of a good technical due diligence engagement isn’t just a risk list—it guides a remediation roadmap. What issues exist, how severe are they, what will it cost and take how long to fix them? That information is directly useful in deal negotiation, integration planning, and setting post-close priorities.
Don’t skip the inspection
Technical debt isn’t a reason not to do a deal. Almost every codebase carries some—it’s the nature of software development under real-world constraints. The question is whether you know what you’re buying.
A thorough pre-acquisition technical assessment gives you that knowledge. It lets you price the deal correctly, plan the integration intelligently, and avoid the unpleasant surprises that have derailed more than a few acquisitions that looked great on paper. Like a home inspection, it’s one of the best investments you can make before you sign.
