Technology due diligence checklist for M&A

Technology due diligence checklist for M&A: a CTO guide to pre-acquisition technology review

In 2025, 45% of dealmakers said technology review was the most expensive and arduous part of M&A due diligence. Half said deals take at least six months end to end, and 59% said diligence adds 1 to 3 months to timelines. That time pressure is exactly when tech risk gets waved through. Then it shows up post-close as a rewrite, a security incident, or a hiring scramble.

Here’s the thesis: CTOs need a repeatable technology due diligence checklist that turns messy inputs into a decision-grade report.

What is technology due diligence, and what does a pre-acquisition technology review cover?

Technology due diligence is a structured audit of a target’s software, infrastructure, security, vendors, and delivery capability. You’re not there to “grade” engineering. You’re there to price risk and map the first 180 days after close.

The Art of CTO Technology Due Diligence tool is a guided five-part assessment. It combines codebase health, architecture maturity, security posture, vendor risk, and tech debt into a single PDF report for M&A, investment, or audit scenarios.

A practical pre-acquisition technology review covers five domains:

Codebase health: code quality, test depth, dependency hygiene, build and deploy reality.
Architecture maturity: service boundaries, data flows, scaling limits, documentation, operational readiness.
Security posture: known vulns, secrets handling, access control, incident history, compliance gaps.
Vendor risk: cloud and SaaS lock-in, license exposure, third-party concentration, contract traps.
Tech debt: where the debt sits, how fast it grows, and what it costs to pay down.

This is what most diligence teams try to do already. The difference is structure and output. SRS Acquiom’s 2025 study calls out how tech review has expanded into data storage, privacy, and security risk, and how missing or incomplete target data slows everything down. That’s the real enemy here. Not lack of tools, but lack of clean inputs and a shared model for decisions. See SRS Acquiom’s M&A Due Diligence Study: 2025 Insights & Trends.

Framing statement: tech diligence is a valuation exercise disguised as an engineering review.

Technology due diligence checklist: what to evaluate in 2 to 4 weeks

Most Series A and B teams can’t pause roadmap work for a month. So the checklist needs two modes: a fast triage in week one, then deeper cuts where the risk is real.

Week 1 triage: find the deal breakers fast

The fastest way to miss risk is to start with opinions. Start with artifacts.

Triage artifacts to request in 48 hours

Repo access: read-only access to core repos, plus CI logs.
Dependency inventory: SBOM if they have it, or lockfiles and package manifests.
Architecture map: even a rough diagram, plus a list of systems of record.
Security evidence: last pen test, vuln scan output, incident summary.
Vendor list: cloud accounts, SaaS list, top 20 contracts by spend.
Delivery data: deploy frequency, lead time, change failure rate, MTTR.

If the target can’t produce these, that’s a finding. SRS Acquiom reports 40% of boutique investment banks cite incomplete target information as a top diligence hurdle. That’s not a paperwork issue. It’s a controls issue. See SRS Acquiom’s study.

Triage questions that surface hidden risk

What breaks if the top two engineers leave next month?
Which customer commitments require manual work every week?
Which system holds the source of truth for identity and billing?
Which third-party contract can’t be assigned on acquisition?

That last one bites more deals than people expect. Holland and Knight calls out “indirect user” licensing and anti-assignment clauses as common traps in software licensing during M&A. See Technology Due Diligence for M&A Transactions: A Primer.

Codebase health: measure maintainability, not style

A codebase can look clean and still be expensive to change. Focus on change cost.

Codebase health checks that correlate with future spend

Build time: under 15 minutes per main pipeline, or engineers stop trusting CI.
Test depth: unit plus integration coverage on core flows, not vanity percent.
Dependency age: count critical packages more than 24 months behind.
Release friction: number of manual steps between merge and production.
Ownership map: clear owners for top 20 modules, not “everyone owns it.”

If you want one metric, use “time to safe change.” Ask for a recent feature PR and trace it end to end. How many files changed. How many reviewers. How many rollbacks. That story beats any dashboard.

Architecture maturity: map the blast radius

Architecture diligence isn’t about microservices versus monoliths. It’s about failure modes and integration cost.

Architecture maturity checks

System boundaries: clear modules, clear APIs, and clear data ownership.
Data flows: where PII lives, where it moves, and who can query it.
Scaling limits: known bottlenecks, plus load test evidence.
Operational model: on-call rotation, runbooks, and incident review habits.
Documentation: diagrams that match reality, updated in the last 90 days.

A simple exercise works well: pick one customer journey, like signup to first invoice. Map every service, queue, and third-party call. You’ll end up with an integration map and a risk map in one pass.

For teams that want to formalize this, pair diligence with our internal guide to architecture decision records and use the ArchiMate Modeler to capture systems, interfaces, and data stores in a way finance and legal can read.

Security posture: treat it as a business continuity review

Security diligence falls apart when it turns into a tool dump. It should answer two questions: what can an attacker do, and what happens to the business if they pull it off.

Black Duck’s M&A checklist highlights why software diligence must cover code quality, security, and open source license obligations, since each can create downstream liability. See Black Duck’s M&A Software Due Diligence Checklist PDF.

Security posture checks that matter in deals

Vulnerability management: patch cadence, SLA, and proof of closure.
Secrets handling: no long-lived keys in repos, rotation evidence.
Access control: SSO, MFA, least privilege, and admin audit trails.
Incident history: last 24 months, plus what changed after each event.
Compliance scope: SOC 2, ISO 27001, HIPAA, PCI, GDPR, and real gaps.

If the target sells to enterprises, ask for their security questionnaire answers. Those answers show what they claim is true. Then compare it to what the systems show.

Vendor risk: price lock-in and contract traps

Vendor risk isn’t only “what if AWS goes down.” It’s “what if we can’t move, even if we want to.”

CAI notes that diligence findings guide TSAs, cloud migration sequencing, and app rationalization. That’s vendor risk in plain terms. See CAI on technology and IT due diligence in M&A.

Vendor risk checks

Concentration: top five vendors by spend and by criticality.
Exit cost: time and dollars to move off the top two vendors.
Contract assignability: anti-assignment clauses, change-of-control triggers.
License exposure: open source obligations and commercial license audits.
Data portability: export paths, retention rules, and deletion guarantees.

A quick win is a “vendor kill switch” table. For each critical vendor, list the outage plan and the exit plan. If either is blank, that’s risk.

Tech debt: quantify it in engineering weeks and dollars

Tech debt gets real the moment it has a price tag.

SIG cites McKinsey research that up to 40% of a technology estate can be consumed by technical debt. SIG also reports that 31% of acquired codebases in their analysis are riddled with technical debt. See SIG on the impact of technical debt in tech investments.

A useful model comes from TheFork’s methodology for remediation cost. They treat remediation cost as a relative estimate that becomes comparable across components. See TheFork on managing technical debt and remediation cost.

A simple diligence-grade debt model

Debt item: what is broken, and where.
Risk class: reliability, security, delivery speed, or compliance.
Effort: engineer weeks to fix, with a confidence band.
Business impact: revenue at risk, churn risk, or support load.
Dependency: what must happen first, like a data migration.

That’s enough to build a post-close plan and to negotiate price or escrow.

Tech due diligence for M&A: the decision this tool helps with

Most CTOs get asked a vague question: “Is the tech good?” That’s the wrong question.

A better question is: What is hiding in this technology stack, and what does it cost to make it safe to scale?

Acquirers often discover post-close that the target’s technology is worth 30% to 50% less than assumed. The drivers are boring and brutal: undocumented systems, key-person dependencies, compliance gaps, and debt that blocks roadmap work.

This is why tech diligence now weighs heavily in deal work. SRS Acquiom reports 45% of participants call technology review the most costly and onerous part of diligence. See SRS Acquiom’s study.

And deal rationale is shifting. PwC’s 2026 outlook notes that technology led megadeal activity in 2025, and that about one-third of the 100 largest corporate M&A transactions cited AI as part of the rationale. They also point to cybersecurity as a prerequisite for scaling AI responsibly. See PwC global M&A trends: 2026 outlook.

So the decision usually isn’t “buy or don’t buy.” It’s one of these:

Buy at the current price and accept the remediation plan.
Buy, but renegotiate price, escrow, or TSA scope.
Buy, but carve out systems and rebuild key parts.
Walk away because the integration cost kills the thesis.

To make that call, CTOs need a report that finance and legal can use. That’s what the tool is built to produce.

The Five-Lens Due Diligence Framework

This guide uses a named model that teams can reuse across deals.

Five-Lens Due Diligence Framework

Lens 1, Codebase health: how hard it is to change.
Lens 2, Architecture maturity: how failures spread and how integration works.
Lens 3, Security posture: how attackers and auditors see the system.
Lens 4, Vendor risk: how contracts and platforms constrain options.
Lens 5, Tech debt: what it costs to reach the next stage of growth.

Quotable definition: Technology due diligence is the act of turning engineering uncertainty into a priced plan.

Software acquisition assessment: a risk and remediation matrix CTOs can use

A software acquisition assessment needs a shared language with the deal team. Use a matrix that ties findings to action.

Finding type	Example	Deal risk	What to ask for	Post-close plan
Codebase health	CI takes 45 minutes, flaky tests, manual releases	Slow integration, missed roadmap	Access to CI logs, release history	4 to 6 weeks to stabilize CI and release
Architecture maturity	Shared database across 6 services	High blast radius, hard carve-outs	Data model, service map	8 to 12 weeks to split data ownership
Security posture	No MFA on cloud console, no incident runbooks	Breach risk, compliance failure	IAM export, audit logs	2 weeks to lock down access, 60 days for controls
Vendor risk	Non-assignable license, change-of-control clause	Surprise cost, legal delay	Contract review, vendor call	Renegotiate or replace in 90 to 180 days
Tech debt	Legacy framework EOL, no upgrade path	Rewrite risk	Dependency tree, upgrade attempts	Budget a rewrite track with milestones

This table also works as a negotiation tool. It turns “we’re worried” into “we need a $1.2M price adjustment or a 12-month TSA.”

For build versus buy calls that come out of diligence, use our Build vs Buy Matrix to document why a rebuild is cheaper than a long migration.

Enterprise implications for Series A and B CTOs

Even small targets create big integration work. Here are the ways this hits CTOs running teams of 10 to 100 engineers.

Deal timelines collide with roadmap reality. Half of respondents in SRS Acquiom’s study report six months or more to close, and diligence often adds 1 to 3 months. That time comes out of engineering focus. Plan capacity like it’s a product launch. See SRS Acquiom’s study.
AI-driven deal theses raise the security bar. PwC notes AI shows up in about one-third of the largest 2025 deals, and cybersecurity is treated as a prerequisite for scaling AI. If the target’s data controls are weak, the AI thesis collapses. See PwC global M&A trends.
Hidden tech debt becomes the biggest integration line item. SIG cites McKinsey research that up to 40% of a tech estate can be consumed by debt. That shows up as delayed features and rising incident load, not as a neat invoice. See SIG on technical debt.
Vendor and license traps create legal and cost surprises. Anti-assignment clauses and indirect user licensing can change the economics of a deal. Legal teams spot the clause, but CTOs need to explain the technical dependency and the exit cost. See Holland and Knight’s primer.

CTO recommendations: how to run a technical audit tool workflow that produces a PDF report

The tool is a guided workflow, but the hard part is leadership. CTOs need to set expectations, protect the team, and keep the output decision-grade.

Immediate actions (first 72 hours)

Name the diligence captain. Pick one engineering leader to run the process. Give them 30% to 50% time for two weeks.
Create a single evidence room. Use one folder with a strict index. Mirror it in your internal Command Center. The goal is one source of truth, not Slack archaeology. Pair this with Command Center to track risks, owners, and deadlines.
Lock the scope to five lenses. Keep the team out of rabbit holes. If a finding doesn’t change price, TSA, or the first 180 days, park it.
Run a one-hour “systems walkthrough” call. Ask the target to demo deploy, incident response, and access control. Screen share beats slide decks.

Policy framework (what to standardize across deals)

Evidence standards. Require artifacts, not statements. “We have backups” becomes “show the restore test from the last 90 days.”
Key-person dependency rule. Any system with one owner gets flagged. The mitigation is documentation plus pairing, not a promise.
License and OSS policy. Require an SBOM or a dependency export. Black Duck’s checklist is a good reference point for why this matters in M&A. See Black Duck’s PDF.
Debt pricing method. Use a consistent remediation cost model. TheFork’s approach works because it stays relative and comparable across components. See TheFork’s methodology.

Architecture principles (how to reduce integration pain)

Boundary clarity. Define systems of record and API contracts early. This reduces TSA scope fights.
Identity first. Unify SSO and MFA before deep integration. This cuts breach risk fast.
Data movement discipline. Map PII flows and retention rules before any data lake work. AI projects amplify bad data controls.
Operational readiness. Require on-call ownership, runbooks, and incident review habits. Use our Incident Postmortem tool to standardize reviews across both orgs.

For teams that want to track delivery impact during diligence, use the Engineering Metrics Dashboard to capture deploy frequency, lead time, and MTTR before and after integration.

Bigger picture: why technology due diligence is now a core CTO skill

M&A is no longer a rare event reserved for public companies. Roll-ups, acqui-hires, and product tuck-ins hit Series A and B teams too. The market also rewards capability buys, especially around data and security. PwC’s deal analysis shows AI has become a stated rationale in many large transactions, and that pushes diligence into data governance and security controls. See PwC global M&A trends.

The uncomfortable truth is that diligence is also culture diligence. A target that can’t produce basic evidence often has weak internal controls. That shows up later as missed deadlines and surprise outages. A target that can produce evidence fast usually has a team that can integrate fast.

What happens when the deal team asks for a yes or no in 10 days? The CTO answer should be “yes, with priced conditions” or “no, because the first 180 days won’t work.” That’s leadership, not gatekeeping.

The question is whether your org can turn unknowns into a plan before the close, or whether you’ll pay for that learning after the close.

Use the tool: Technology Due Diligence

Technology Due Diligence Checklist for M&A: A CTO Guide to Pre-Acquisition Technology Review