Security

Technical Due Diligence When Selling a SaaS: What Buyers Examine

The technical workstream of a SaaS sale: what buyers review, how code access should be staged, and the documentation that de-risks a solo-founder codebase.

Iuliia ShnaiUpdated August 20, 20269 min read

Technical diligence answers the buyer's quiet fear: can someone who is not you run this thing? For solo-founder SaaS especially, the codebase, infrastructure, and deployment knowledge are the asset, and the review probes how transferable they really are.

Sellers control more of this outcome than they expect: the difference between a smooth technical review and a scary one is mostly documentation prepared in advance.

What buyers review

  • Architecture: services, data stores, queues, and how they connect
  • Dependency health: framework versions, EOL exposure, license types
  • Infrastructure: hosting setup, costs, scaling behavior, single points of failure
  • Security: authentication, secrets handling, backups, incident history
  • Development process: tests, CI/CD, deployment frequency, rollback story
  • Operational knowledge: runbooks, monitoring, what breaks and how it gets fixed

The key-person audit

The sharpest technical question in a founder-run SaaS is not code quality, it is bus factor: undocumented deploy steps, credentials in one person's password manager, tribal knowledge about the one cron job that must never run twice. Buyers discount hard for it because they are pricing their first three months of ownership.

The fix is a transition file: runbooks for deployment, incident response, and routine operations, an access inventory of every credential and where it lives, and an honest known-issues list. Sellers who produce this unprompted routinely earn it back in price and speed.

Staging code access

Code is the last thing disclosed, and never through the data room itself. The standard sequence: architecture documents and dependency reports in the room under NDA, then a guided walkthrough by screenshare, then time-boxed read-only repository access for the buyer's reviewer in late diligence, logged and revocable.

Document each access grant in the room alongside the NDA, so the audit trail of who saw the code, when, under what terms, lives with the rest of the deal record. Watermarked architecture docs and per-buyer permissions, the controls rooms like Papermark are built around, cover the pre-code stages.

Red flags, and the cheap fixes

Red flagBuyer's readPre-sale fix
No staging environmentEvery deploy gambles productionStand one up; document the pipeline
Secrets in the repoSecurity culture riskRotate and move to a secrets manager
Copyleft license in core codeIP contamination questionLicense audit and replacement plan
No backups testedData loss exposureTest a restore; document the procedure
One-person deploy knowledgeTransition riskRunbook plus a recorded walkthrough

Next steps

FAQ

Do buyers always review code before buying a SaaS?

Above trivial deal sizes, yes, though depth varies: micro-acquisitions may settle for a walkthrough and dependency report, while larger deals bring a technical reviewer into the repository under access controls.

Should I give buyers access to my production systems?

No. Diligence works from documentation, walkthroughs, and read-only code access. Production access transfers at closing, through a planned credential handover.

How do I protect my code during diligence?

NDA first, staged disclosure, read-only time-boxed access late in the process, and a logged record of every grant. Serious buyers expect and respect the sequence.