Technology Due Diligence Checklist for Private Equity and Mid-Market Acquirers

A PE firm closed on a $45M specialty SaaS company last quarter. Diligence looked strong on paper. The stack was modern. SOC 2 was current. A third-party code scan returned a respectable score. The operating partner signed off, the deal closed, and the value-creation plan kicked off on day one.

Five months later the integration was nine months behind. A single senior engineer had resigned two weeks after close and taken the only working knowledge of the payment reconciliation module with him. The data model in the target's core product did not map cleanly to the platform the PE firm intended to consolidate onto. And the "modern stack" turned out to include a framework version two majors behind current, wedged in place by custom patches that made an upgrade a six-month project before integration could even start.

Total impact: $2.3M in unplanned remediation spend, a full year added to the integration roadmap, and a revision to the LP return model in the next quarterly update.

This pattern is not rare. It is the default outcome when diligence covers what it is easy to check and leaves what actually determines outcomes for post-close discovery.

Below is the checklist our team runs for PE operating partners and mid-market acquirers. It is structured so findings translate directly into line items in the deal model — not narrative risks that get filed and forgotten.

Section 1 — The Usual Checks (Table Stakes)

These are the items most diligence processes already cover. They are necessary but they do not separate a successful acquisition from an expensive one.

• [ ] Stack inventory. Languages, frameworks, databases, cloud services. Current versions. End-of-life dates.
• [ ] Infrastructure posture. Hosting provider, redundancy, backup cadence, RTO/RPO, disaster recovery tested in last 12 months.
• [ ] Security and compliance. SOC 2, HIPAA, PCI as applicable. Last penetration test date and high-severity findings. Dependency scan results.
• [ ] License audit. Commercial licenses for every paid dependency. No GPL-tainted components in proprietary paths.
• [ ] Code quality signals. Test coverage, build/deploy frequency, mean time to restore for production incidents over trailing 12 months.

If diligence stops here, you have a stack inventory — not a decision-quality assessment.

Section 2 — Leadership Execution Capability

The biggest single predictor of integration success is whether the current technology leadership can specifically execute the transformation the deal thesis requires. This is different from general competence.

• [ ] Has the current CTO (or top technical lead) managed an integration of this scale before? Not "shipped product" — specifically managed two previously independent codebases, teams, or data models being combined. Ask for references from prior integrations.
• [ ] What is the retention risk profile for the top 5 technical contributors? Compensation, equity vest, length of service, any pending moves. A resignation in the first 90 days from any of these five can add six months to a timeline.
• [ ] How is the engineering team structured today and how will it need to restructure? If the target runs a single cross-functional team of ten and the integration plan assumes three domain teams of four, the restructuring is itself a project and its risk should be priced.
• [ ] Who makes architecture decisions today? If it is one person, the integration will move at the pace of that person's bandwidth.
• [ ] Is there documented capacity planning? Can leadership accurately answer: given the integration backlog plus committed product roadmap, how many FTEs will be at risk of burnout in months 3-9?

Section 3 — Knowledge Concentration Risk

In mid-market companies, institutional knowledge is almost always concentrated in a handful of individuals. The diligence question is not whether this is true but how bad it is.

• [ ] Map each critical system to the engineers who can modify it without breaking it. If any system has fewer than two people who meet that bar, it is a single-point-of-failure risk.
• [ ] Ask: if your top engineer left tomorrow, which systems would be immediately at risk? The answer is diagnostic. A CTO who says "none" has not thought about it. A CTO who names three or four has.
• [ ] Inspect the runbooks. Every critical system should have a written runbook that a qualified engineer not previously on that system could use to respond to a production incident. Count the systems with a current runbook and the ones without.
• [ ] Review the on-call history. Who has carried the pager? If the same two people have been primary for 80% of the incidents over the last 12 months, that is concentration risk.

Section 4 — Integration Surface Area

Architecture diagrams show shape. They do not show how hard it is to connect the target system to anything else.

• [ ] Every external API: is it documented, versioned, and actively maintained? "Documented" means a third-party developer could integrate without asking the original author a question.
• [ ] Data model alignment. Can the target's core entities (customers, orders, products, whatever drives the business) be mapped to the acquirer's model without loss? If not, budget the data transformation work explicitly.
• [ ] Authentication and identity. How will users move from the target's system to the combined platform? SSO-compatible? Migration path for existing accounts?
• [ ] Observability. Will the target's logs, metrics, and traces flow into the acquirer's monitoring stack? Or will integration require rebuilding observability from scratch?

Section 5 — Technical Debt That Actually Matters

Technical debt estimates are usually presented as a percentage. That number is almost always meaningless without context. The question is not "how much debt" but "what does the debt prevent you from doing."

• [ ] Identify the 3-5 pieces of technical debt that block the integration plan. Not all of it. The parts that sit between today's system and the target-state architecture.
• [ ] For each blocking item, estimate remediation cost in weeks of senior engineering time. Compare to the integration timeline. If remediation consumes more than 20% of the available capacity, the timeline is not realistic.
• [ ] Flag any dependency that is more than two major versions behind. Upgrading is always more expensive than it looks and is rarely a one-week project.
• [ ] Identify any custom-patched dependency. Patches to open source libraries mean upgrades require re-applying the patches, testing, and maintaining a fork. Every custom patch is a tax on every future upgrade.

Section 6 — Vendor and Supply Chain Risk

Mid-market companies frequently run on a handful of third-party services where a vendor problem becomes a deal problem.

• [ ] List every vendor in the critical path. Payment processor, email provider, authentication provider, primary cloud, any SaaS that would cause an outage if it went down.
• [ ] Review the contract renewal dates. A critical vendor coming up for renewal in the 12 months after close is either an opportunity (consolidate, renegotiate) or a risk (vendor lock-in, price increase).
• [ ] Flag any single-vendor dependencies without a documented migration plan. Not every dependency needs a fallback plan, but critical-path vendors do.

Section 7 — Deal-Thesis Alignment

This is the section most diligence skips entirely. It is the one that actually determines whether the technology supports or undermines the return model.

• [ ] What does the value-creation plan require the technology to do? New markets, new products, consolidated platform, reduced operating costs? Each has different technology implications.
• [ ] Can the current architecture support that requirement? Not "could it, in theory, be modified" — is it fundamentally structured in a way that allows the change without a ground-up rebuild?
• [ ] What is the rebuild-vs-remediate trade-off? If remediation is 60% of the rebuild cost, rebuild usually wins on time-to-value. Diligence should surface this calculation, not leave it for the first board meeting.

How to Use This Checklist

Most buyers who receive a checklist like this check the boxes and move on. That is not the point.

Each unchecked item is either a finding or an unknown. Findings go in the deal model. Unknowns get verified before close. The goal is not a complete checklist — it is a diligence process where the acquirer knows what they are buying before the wire goes out.

If you want a second set of eyes on a specific deal, we run this assessment on a compressed timeline for mid-market acquirers and PE operating teams. It takes 10-14 days and produces a report that translates directly into the deal model, the integration plan, and the value-creation roadmap.

Book a call to discuss a specific deal.