M&A Technical Due Diligence: The Case for and Against

Assume that any technical asset not explicitly audited is a liability until proven otherwise; this rule holds unless the acquisition is a "talent-only" acqui-hire where the existing codebase is intended for immediate decommissioning.

M&A technical due diligence is the process of verifying that the technology a buyer is paying for actually exists, functions as claimed, and does not carry hidden costs that erode the deal's internal rate of return. While financial due diligence focuses on what has happened, technical due diligence predicts what will happen during integration. The tension in any deal arises from the cost of the audit versus the risk of the unknown. A lean approach saves time and consultancy fees but leaves the acquirer exposed to "technical debt": the accumulated cost of quick-fix software decisions that must eventually be repaid through expensive refactoring.

The argument against extensive technical due diligence usually centres on deal velocity. In competitive bidding wars, the party that moves fastest often wins. Proponents of a light touch argue that deep code reviews and infrastructure audits can spook a seller or delay a closing by months. However, this is a gamble on the target's honesty. As noted by the Zartis team, neglecting these hidden threats is a primary reason why 70-90% of mergers fail to achieve their goals. When a buyer skips the technical audit, they are not removing risk; they are simply deferring it to the post-merger integration phase, where the cost of remediation is typically higher and the leverage to renegotiate the price is gone.

The case for rigorous diligence is anchored in valuation accuracy. Technical debt is a financial liability. If 33% of developer time is wasted on technical debt, as suggested by a report from Developer Coefficient cited by Zartis, the buyer is effectively paying for a workforce that is one-third less productive than it appears. This affects the scalability of the business. A system that works for 10,000 users may collapse at 100,000 if the architecture is monolithic and fragile. Without a technical audit, the "growth potential" cited in the investment thesis is a hypothesis rather than a fact.

Beyond the buyer's perspective, there is a strong case for sell-side diligence. According to Ansarada, half of all deals fail due to issues surfaced during the due diligence process. A seller who performs a self-audit identifies and rectifies gaps before the buyer's team arrives, which often results in a higher final valuation and a more streamlined closing process.

The risk of a cursory review extends into the very structure of the organisation. As Windsor Drake observes, a thorough review must cover infrastructure, software reliability, data protection, and team expertise to avoid inheriting outdated systems or expensive debt.

Technical risk is a measurable variable that should be used to adjust the purchase price.

Pre-LOI: Strategic Alignment Checks

These checks occur during initial conversations to determine if the target is even worth the cost of a full audit.

• The target's primary value proposition is driven by proprietary technology rather than just market share.
• The technical leadership can provide a high-level architecture diagram without more than 48 hours of lead time.
• The target's growth projections do not require a total rewrite of the current platform to achieve.
• There is clear evidence of a version-controlled codebase (e.g., GitHub or GitLab).

Cost of failure: Proceeding to a full audit on a company with no documentation or a "black box" architecture wastes significant consultancy spend and often leads to an immediate deal break.

Phase I: The Structural Audit

Once a Letter of Intent is signed, the focus shifts to the viability of the assets. This is where you validate the "what" and the "how".

• All critical software components are owned by the company or covered by transferable licenses.
• The codebase is modular enough that a single failure does not take down the entire system.
• There is a documented roadmap that aligns with the acquirer's strategic goals.
• The team has a documented process for deployment and testing that is actually followed.

Cost of failure: Discovering non-transferable licenses or "spaghetti code" after closing leads to immediate unplanned capital expenditure to replace core systems. For more on spotting these structural flaws, see Cloud Architecture Due Diligence: What to Look For.

Phase II: Risk and Exposure Audit

This phase identifies the "landmines" that could lead to legal penalties or catastrophic downtime.

• The company has a current, tested disaster recovery plan with a defined Recovery Time Objective (RTO).
• All open-source components are indexed and comply with their respective licenses (e.g., avoiding restrictive GPL leaks).
• Data encryption is implemented for both data at rest and data in transit.
• The target has no undisclosed historical breaches or ongoing security incidents.

Cost of failure: Inheriting an active breach or a GDPR violation can result in fines that exceed the perceived value of the acquisition. This stage is often where Cybersecurity Due Diligence: Where to Start provides the most leverage for price renegotiation.

Phase III: Human Capital and Process Audit

Technology is a product of the people who build it. This phase assesses whether the knowledge stays after the founders exit.

• Critical system knowledge is documented in a wiki or handbook rather than existing solely in the heads of two key engineers.
• The turnover rate of the engineering team is within industry norms for the target's growth stage.
• The development velocity is consistent and not dependent on extreme overtime.
• There is a clear succession plan for the CTO or lead architects.

Cost of failure: If the "key person" leaves post-acquisition and the systems are undocumented, the buyer inherits a "legacy system" they cannot maintain or update.

Valuation Impact Matrix

The findings of the checklist above should be mapped directly to the deal price. Technical risk is a discount factor.

The goal of technical due diligence is not to find a perfect company (those rarely exist) but to ensure the price paid reflects the reality of the code.

Sources

• Technology Due Diligence In M&A: Covers the basics of buy-side and sell-side IT auditing and timeframes.
• Technical Due Diligence: The $3.4T Secret Weapon in Modern M&A: Provides failure rates of mergers and the impact of technical debt on developer productivity.
• Technology Due Diligence in M&A | Windsor Drake: Details the four main areas of TDD including infrastructure, software reliability, data protection, and team expertise.