Sell-Side Technical Due Diligence: How Founders Prepare Before Going to Market

Sell-side technical due diligence is an independent technology assessment that a founder commissions on their own company before going to market. It finds the issues a buyer's technical team would find, early enough to fix them or disclose them with a costed plan. Started at least 60–90 days before a sale process launches, it gives founders more control over the price conversation and tends to mean cleaner LOI terms and a shorter buyer diligence phase.

This article is written for founders, CEOs and CTOs preparing for a sale or a significant raise. It explains what sell-side technical diligence covers, when to start, what buyers will look at, a step-by-step preparation plan, and whether to share the resulting report with bidders.

What Is Sell-Side Technical Due Diligence?

In a typical deal, the buyer hires a firm to examine the target's software, infrastructure, security and engineering team. Sell-side technical due diligence runs that same review earlier, on the seller's behalf. The assessors are independent, but the timing, the scope and what happens with the findings are under the founder's control.

It sits alongside the financial preparation most sellers already do, such as a quality-of-earnings review. In some processes the output becomes a vendor due diligence report shared with bidders; in others it stays internal and is used purely to prepare. Either way, the questions are the ones a buyer will ask, and the standard of evidence is the one a buyer will apply.

Sphere's technical due diligence practice works on both sides of the table, including founders preparing for a transaction well before they need to. The method is the same as buy-side work; only the client and the purpose change.

Why Run Technical Due Diligence on Your Own Company?

For a founder, the case is about control rather than compliance.

• No surprises in the room. You learn what a buyer will find before they do, and you decide how it is presented.
• Cheap fixes get done. Leaked secrets, outdated dependencies, licence conflicts and missing documentation are often quick to resolve, and each one removed is one less negotiating point.
• Expensive issues get a price. Problems that cannot be fixed in time can be costed and planned, so the buyer debates a number rather than an open-ended risk.
• A faster, calmer process. When the data room is complete and the answers are consistent, the buyer's diligence moves faster and deal fatigue is lower.
• Credibility with the buyer's engineers. A CTO who already knows the weak spots, and has a plan for them, reads as a leader worth retaining.

The alternative is what happens when the buyer finds the issues first. In Sphere's diligence for Careismatic Brands' acquisition of SellersCommerce, the buyer-side assessment surfaced three critical risk areas: architecture fragility, onboarding friction and infrastructure scaling costs. The deal team used the report to negotiate enhanced representations and warranties and a technology escrow, and avoided an estimated 6–12 months of post-acquisition rework. That is good diligence for a buyer. For a seller, every one of those terms is value given away at the table.

When Should Founders Start Preparing for Technical Due Diligence?

Earlier than most do. What you can achieve depends on how much runway you have before the process launches.

What Will the Buyer's Technical Team Look At?

Buyers' assessors work from a broadly standard list. Our software due diligence checklist sets it out in full from the buyer's side; in short, expect questions on:

• Architecture and scalability: can the platform carry the growth plan the price assumes?
• Code quality and technical debt: how much deferred work will the new owner inherit, and what will it cost?
• Security and compliance: vulnerabilities, access controls, incident history and regulatory exposure.
• IP and open-source licensing: clear ownership of the code and no licence terms that conflict with the business model.
• AI-generated code: how much was written with AI tools and how it was reviewed. Buyers increasingly check this as a separate risk, as our piece on diligence for AI-built codebases explains.
• Engineering team: key-person risk, retention and whether the team can execute the roadmap.
• Infrastructure and cost: cloud spend, vendor lock-in and continuity planning.

Earlier-stage companies face a lighter version of the same review; the technical due diligence checklist for startups covers what investors check in a funding round.

How Do You Prepare for Technical Due Diligence? A Step-by-Step Plan

The sequence below works whether you have 18 months or 90 days. The time available decides how far you get through step three.

Two points are worth stressing. First, independence matters more on the sell side, not less. A buyer will discount a report from a firm that also stands to win the remediation contract. Sphere's diligence practice does not sell implementation services to companies it assesses, which is one reason its findings hold up under a buyer's scrutiny.

Second, remediation needs capacity. If the core team is fully committed to the roadmap, fixes slip until the process is underway. Bringing in temporary engineering capacity is common; our overview of software staff augmentation explains how teams add it without disrupting delivery.

Long-running debt deserves its own plan rather than a scramble. Our guide to technical debt for business leaders is a useful primer for the non-technical members of the deal team.

What Belongs in the Technology Section of the Data Room?

A well-prepared technology section answers most first-round questions without a meeting:

• Current architecture diagrams, as built rather than as planned.
• A dependency inventory with licences, plus recent security scan and penetration test results.
• An incident log and a summary of how each incident was resolved.
• Infrastructure costs by service and the main vendor contracts.
• Engineering org chart, tenure and ownership of each core system.
• Development process: branching, review rules, CI/CD, testing and release cadence.
• Your AI usage policy and the AI coding tools in use.
• The remediation plan for any issues you are disclosing, with costs and dates.

Consistency is the real test. If the data room says one thing and the CTO says another in the management meeting, the buyer will start digging.

Should You Share the Sell-Side Report With Buyers?

There are three common choices, and each suits a different process.

1. Keep it internal. The report is a preparation tool. You fix what you can and go into the buyer's diligence knowing the answers. This suits smaller or bilateral processes.
2. Share a summary. Bidders get the scorecard, the key findings and the remediation plan. This sets the agenda and anchors the conversation on your numbers.
3. Share the full report. Common in competitive auctions, where a vendor report lets several bidders move quickly on the same facts. Expect buyers to verify the main findings rather than accept them outright.

Whatever you choose, the format matters. Buyers read diligence reports in a familiar structure: a verdict, a scorecard, costed findings and a roadmap. Our walk-through of what goes into a technical due diligence report shows the sections a buyer will expect to see.

For a complete view of scope, process and choosing a provider, see the technical due diligence and code audit guide.