Technical Due Diligence for M&A: What to Review

What technical due diligence means

Technical due diligence is an engineering review of a company’s technology before an acquisition or investment. It tests whether the product, systems, code, and team can support the business plan. Buyers use it to find risks, check growth potential, and spot costly technical debt.

The review is not a full rebuild or a guarantee that every defect will surface. It gives deal teams a grounded view of the technology they may acquire. Findings can shape the price, deal terms, integration plan, or decision to walk away.

Scope depends on the target. A small software firm may need a focused code and security review. A larger company may also need checks on cloud costs, data handling, vendor ties, and many product systems.

What the review should cover

A sound review joins engineering, security, and business questions. The aim is to see how the technology works today and whether it can meet the company’s plans. Assessors should test key claims against evidence, not rely on slides or interviews alone.

Code review can reveal fragile parts, poor test coverage, and hard-to-change systems. Architecture assessment looks at how parts fit together and where failure could spread. Infrastructure assessment checks uptime, backup plans, cloud spend, and the path to add users.

Security and compliance checks matter because a deal can inherit weak controls or legal risk. Review access rules, data flows, known flaws, incident records, and required standards. The NIST Cybersecurity Framework offers a trusted way to frame security risk checks.

Also review intellectual property, product plans, and the technical team. Confirm the target owns or can use its key code and tools. Check whether a few staff hold vital system knowledge, and whether the team can ship and support planned growth.

• Code: design, test coverage, defects, and build process
• Systems: architecture, uptime, backups, and growth limits
• Security: access, data safety, incidents, and open flaws
• People and rights: team skills, key roles, and code ownership

How the technical due diligence process works

A typical technical due diligence process takes two to four weeks. Cost often falls between $5,000 and $30,000, based on scope, company size, and system complexity. Tight timelines or many products can raise the fee.

Start by agreeing on the technical due diligence scope of work. Set the deal context, review areas, access needs, deadlines, and final outputs. Name one contact on each side, then collect system maps, code access, security records, product plans, and team details.

Next, interview leaders and engineers, then test the most important claims. Review code samples, cloud setup, release steps, and incident records. Ask for evidence when answers seem broad or conflict with what the team has shared.

Close with a ranked report. Separate urgent risks from work that can wait, and state how each issue affects cost, growth, or deal value. Give the buyer time to ask follow-up questions before the team sets final terms.

1. Set the scope. Tie review areas to the deal thesis and the target’s main products.
2. Gather evidence. Request code, system records, policies, plans, and key staff access.
3. Test and interview. Check claims, trace risks, and ask follow-up questions.
4. Rank findings. Explain impact, likely effort, and next steps for each major risk.

A technical due diligence checklist to use

A checklist helps teams cover the same core areas and record missing proof. Adapt it to the deal rather than treating every question as equal. A firm that sells a simple app needs a different review from a firm with sensitive data or complex systems.

Use a shared spreadsheet or workbook to track evidence, owners, risk level, and open questions. A technical due diligence checklist PDF can work for a quick review, but a spreadsheet is easier to sort and update. Keep a record of who supplied each item and when.

Documentation quality is a useful signal. Missing system maps may slow future work, while unclear ownership can put core code at risk. Check integration capabilities early if the buyer plans to connect products, data, or staff systems.

Red flags that can change a deal

Technical debt is not always a reason to stop a deal. The key question is whether the debt blocks growth, raises failure risk, or takes more money to fix than expected. Ask the team to show the highest-cost issues and explain their plan to address them.

Compatibility issues can make a planned merger far harder. Two products may use different data models, cloud tools, or sign-in systems. If the buyer expects a fast merge, test that path with engineers before setting a firm timeline.

Other warning signs include repeated outages, weak backups, unpatched flaws, and one person who alone knows a key system. Missing rights to code or key vendor terms can also threaten product use. Treat claims without evidence as open risks, not as proof that no issue exists.

• Core code has little test cover or no clear owner
• Recovery plans exist on paper but have not been tested
• Security flaws stay open without a named owner or due date
• Growth plans rely on systems with known capacity limits
• Key product rights, contracts, or data terms are unclear

How to make the review useful

Begin with the deal thesis. If value depends on rapid growth, focus on scale, reliability, and team capacity. If value rests on a product asset, focus on code quality, rights, and the cost to keep it running.

Use technical due diligence questions that ask for proof and impact. For example: “What fails first if users double?” or “When did the team last test a full restore?” Ask engineers to walk through real examples, not just give yes-or-no answers.

Keep the tone fair and focused. A review works best when staff know why the buyer needs access and how findings will be used. Limit data access to what the review needs, and use safe handling rules for code and customer records.

Link each issue to a business outcome. Estimate time, cost, staffing, and any risk to customers. This helps leaders compare technical findings with other deal risks and decide which issues need a price change, a fix, or a clear plan.

After the review: turn findings into action

Once the review ends, sort findings by urgency and deal impact. Put serious security or ownership risks in front of the deal team at once. Add smaller fixes to a post-close plan with owners, dates, and budgets.

Integration should not begin with a broad rewrite. First protect service uptime, access, backups, and key staff knowledge. Then map which systems should stay, join, or retire, based on the buyer’s goals.

Track progress after close with a short list of measures. These may include outage time, open high-risk flaws, cloud cost, release pace, and key staff retention. Revisit the plan as the combined team learns more about the systems.

The value of due diligence comes from acting on what it finds. A clear record of risks and choices can keep teams from repeating tests or losing context. It also helps leaders fund the work that protects the deal’s value.