Technical debt is the most consistently underestimated risk in technology acquisitions. Unlike a security breach or a scalability failure, it does not announce itself dramatically. It accumulates quietly — in codebases that were built under pressure, in shortcuts that made sense at the time, in systems that work well enough today but become increasingly expensive to maintain, extend, and integrate as time goes on.

By the time an acquirer discovers the true extent of it, the deal is closed, the price is paid, and the remediation cost is theirs to absorb.

What Technical Debt Actually Is

Technical debt is the accumulated cost of taking shortcuts in software development. Every time a team prioritises speed over quality — implementing a quick fix rather than a proper solution, skipping tests to hit a release deadline, leaving documentation for later — they are borrowing against the future. The debt accrues interest in the form of slower development, higher defect rates, and increasing difficulty making changes without breaking something else.

In a growing startup, some level of technical debt is almost inevitable and entirely rational. The problem is not its existence. It is the extent of it, the visibility of it, and whether the team managing it has a credible plan for addressing it — or has simply stopped noticing it.

Why It Goes Undetected in Due Diligence

Technical debt is invisible to most due diligence processes. It does not show up in financial statements. It does not appear in customer satisfaction scores. It is not mentioned in management presentations — at least not at its true scale. And it cannot be identified through a high-level technical conversation or a brief review of architecture documentation.

Surfacing technical debt requires direct access to the codebase — and the expertise to know what you are looking at when you get there. Automated analysis tools can identify some categories of debt quickly: outdated dependencies, low test coverage, code complexity metrics. But the most consequential debt — the architectural decisions that constrain the entire platform, the undocumented business logic that only two people understand, the accumulated workarounds that make every change a risk — requires human judgment from experienced engineers who have seen these patterns before.

This is precisely why independent, code-level technology due diligence exists. And precisely why skipping it is so often costly.

The Five Ways Technical Debt Destroys Post-Acquisition Value

1. It inflates the cost of every future development cycle. A high-debt codebase is slower and riskier to change. Features that should take weeks take months. Engineers spend more time understanding existing code than writing new code. Every sprint carries hidden overhead that was not in anyone’s model.

2. It delays integration. For acquirers with a platform or buy-and-build strategy, integration is central to the value creation thesis. Technical debt makes integration dramatically more complex — tightly coupled systems resist clean API integration, and undocumented components create unpredictable dependencies that only reveal themselves mid-project.

3. It competes with the product roadmap. Debt remediation is not optional indefinitely. At some point, the accumulated shortcuts become a constraint on what the platform can do. When that point arrives post-close, the acquirer faces a choice between remediating debt and delivering the roadmap — and usually cannot do both at the same time.

4. It increases staff turnover. Engineers do not enjoy working in high-debt codebases. The frustration of dealing with fragile, poorly documented systems with no clear improvement plan drives attrition — particularly among the stronger engineers who have options. Losing engineering talent post-acquisition is expensive and disruptive, and technical debt is a more common driver of it than most acquirers anticipate.

5. It conceals other risks. High levels of technical debt are often correlated with other problems: inadequate security controls, poor testing discipline, limited operational monitoring. A codebase that was not built carefully tends not to have been secured carefully either. Technical debt is frequently a leading indicator of broader technical risk.

The Types of Debt That Hide Best

Not all technical debt is equally visible — even to a code-level assessment. The most damaging categories are also the hardest to find:

Architectural debt — fundamental design decisions that constrain the platform’s scalability, extensibility, or integrability. This is not visible in individual files or functions; it requires understanding the system as a whole.

Documentation debt — the absence of documentation for critical components, business rules, or integration points. This type of debt does not produce an error. It simply means that knowledge lives exclusively in the heads of people who may or may not still be with the company post-close.

Test debt — the absence of automated tests across critical system paths. Low test coverage is not just a code quality indicator. It is an operational risk: every change to an untested codebase is a potential source of undetected defects in production.

Dependency debt — reliance on outdated, unmaintained, or end-of-life third-party libraries and frameworks. These create security exposure and impose constraints on future development that are often underestimated at acquisition.

Quantifying Debt Before You Sign

The goal of technical debt assessment in due diligence is not simply to identify that debt exists — it is to quantify it with enough precision to inform the commercial decision. How much will it cost to remediate? How long will it take? What is the impact on the post-close development roadmap if remediation is deferred?

These are answerable questions — but only with access to the codebase and the expertise to assess what is there. An experienced TDD team can translate technical findings into commercial terms: remediation costs, timeline estimates, and a prioritised view of what needs to be addressed immediately versus what can be managed over time.

That translation — from code to commercial decision — is the core of what technology due diligence delivers.

At VeryDiligent, technical debt assessment is a central component of every technology due diligence engagement. We give investors and acquirers a clear, quantified view of what they are inheriting — so that the price they pay reflects the true cost of the technology they are acquiring.

Contact us today to discuss your upcoming transaction.

Related reading: How Technical Risk Impacts Valuation Multiples | Legacy Systems in M&A: The Technical Risks Investors Miss | What Questions to Ask a CTO During Due Diligence