When founders prepare for a seed round, Series A or strategic acquisition, almost all the preparation goes into the pitch deck, financial models and customer retention metrics. But once term sheets are on the table, investors bring in external engineering auditors to inspect what is actually happening behind the curtain.
Technical due diligence is not a university code grading exercise. Seasoned technical auditors are not looking for academic perfection or whether you used every trendy design pattern. They want to answer three straightforward questions: Will this software break if the user base grows tenfold? Is there critical intellectual property risk? How dependent is this entire system on a single person's memory?
Having led technical audits on both sides of the table, here are the core areas technical auditors examine and how you can prepare your stack ahead of time.
1. Codebase Maintainability and Architecture Sanity
Auditors will clone your primary repositories and inspect your project structure, Git commit history and automated test coverage. They look for red flags like five-thousand-line monolithic files, commented-out dead code from two years ago, hardcoded credentials and an absence of linting rules.
You do not need 100% test coverage to pass due diligence. What impresses auditors is thoughtful coverage on critical business workflows: user authentication, payment processing and core calculations. Ensure your repository has a clean README that explains local setup steps, architecture boundaries and deployment commands in plain language. If an auditor can clone your repo and run the test suite in under ten minutes without messaging you for hidden environment variables, you start from a position of strength.
2. Open-Source Licensing and IP Compliance
This is where deals often hit unexpected delays. If your engineering team copied open-source code with copyleft licenses (like GPL-3.0 or AGPL-3.0) directly into your proprietary product codebase, your company could face legal obligations to open-source its own commercial software.
Run an automated software bill of materials (SBOM) audit using tools like FOSSA or GitHub dependency graph. Identify every third-party package and ensure all dependencies use permissive licenses (such as MIT, Apache-2.0 or BSD-3-Clause). Document any external APIs, third-party datasets or contractor assignment agreements so you have clear paperwork proving your company owns its code.
3. Infrastructure Security and Access Governance
Auditors will ask to see your cloud console permissions, production database access policies and secrets management practices. Red flags include root AWS accounts shared across five engineers, production database passwords stored in unencrypted .env files and former contractors who still have active Git write access.
Enforce multi-factor authentication (MFA) across all developer accounts. Rotate any production keys that have lived in plain text and migrate secrets into managed services like AWS Secrets Manager or Infisical. Show auditors that access follows the principle of least privilege: developers should not have direct, unlogged write access to production customer databases during normal day-to-day work.
4. Technical Debt and Single-Point-of-Failure (Bus Factor) Risk
The most dangerous finding in an audit report is that the entire company depends on one person who keeps all system knowledge in their head. If your lead engineer got hit by a bus tomorrow, could the remaining team deploy a critical security patch or restore a corrupt database from backups?
Document your disaster recovery playbooks. Write down how a new developer sets up their machine, how code reaches production and where automated database backups live. When an investor sees that your operational knowledge is documented and repeatable, their confidence in your team skyrockets.
Conclusion
Technical due diligence should not feel like an ambush. It is an opportunity to prove that your software is a durable asset rather than a fragile prototype held together with duct tape. Clean up your dependencies, document your critical workflows, lock down your production credentials and you will turn technical inspection into a powerful catalyst for closing your round.