How to Run a Technical Due Diligence Review on Your Own Codebase

When to Use This

60–90 days before you start Series A fundraising conversations.

Why This Matters

Most founders experience technical due diligence as something that happens to them. Investors commission an external reviewer, the reviewer spends a week with your codebase, and you get a report of gaps you had no idea existed.

Running your own review first changes the dynamic entirely. You close the obvious gaps, you understand your risk areas, and you go into investor conversations with a clear-eyed view of your engineering maturity.

Step 1: Assess Reliability

• What was your uptime over the last 90 days?
• Do you have monitoring that alerts you before a user reports a problem?
• Have you had production incidents? How long did they take to resolve?

Red flags: no uptime monitoring, incidents discovered via user reports, resolution time measured in hours.

Step 2: Assess Security

• Are all secrets managed via environment variables or a secrets manager — not hardcoded?
• Are dependencies audited for known vulnerabilities? (Run npm audit or pip-audit right now.)
• Is data encrypted in transit and at rest?
• Do you have a clear data retention policy?

Red flags: API keys in git history, no dependency scanning, no HTTPS on any endpoint.

Step 3: Assess Recoverability

• When did you last test restoring from a database backup?
• Do you have a documented recovery plan for a production outage?
• What is your Recovery Time Objective (RTO) and Recovery Point Objective (RPO)?

Red flags: backups exist but have never been tested, no documented recovery process, no defined RTO.

Step 4: Assess Scalability

• Could the system handle 10× current load without a rewrite?
• Where are the known bottlenecks?
• Have you load tested the critical user journeys?

Red flags: database queries without indexes on frequently-queried columns, synchronous calls to slow external services on the critical path, no knowledge of where the bottlenecks are.

Step 5: Assess Maintainability

• Could a new senior engineer understand the system in one day with documentation?
• What is the test coverage on critical paths (auth, payments, core business logic)?
• Are the top three architecture decisions documented with their rationale?

Red flags: no README beyond setup instructions, no tests on payment or auth flows, architecture that exists only in the founding engineer's memory.

Step 6: Assess Team Risk

• If your most critical engineer left tomorrow, which parts of the system would be most at risk?
• Is there a single person who wrote the majority of the system and is the only one who understands it?
• Is deployment documented so that more than one person can do it?

Red flags: one person who owns 80% of the system, deployment that only happens when a specific person is available.

Step 7: Assess Operational Readiness

• Is deployment automated via CI/CD?
• Is there a documented incident response process?
• Are runbooks written for the most common operational tasks?

Red flags: manual deployments, no CI/CD, first time an incident process is defined is during an actual incident.

Scoring Your Results

For each of the seven areas, score 1–3:

• 1 — not in place, would be flagged immediately in due diligence
• 2 — partially in place, some risk but explainable
• 3 — in place and documented

A score of 17 or above (out of 21) means you are in a solid position. Below 14 means you have material gaps to close before fundraising conversations begin.

Common Mistakes

Running this review too close to fundraising

60–90 days minimum. Some gaps — test coverage, documentation, CI/CD — take real time to close properly.

Closing gaps cosmetically

Writing a recovery plan that nobody has tested, or adding monitoring that nobody checks, creates the appearance of readiness without the substance. Investors often probe these in conversations.

Skipping the team risk section

This is the one most technical founders avoid because it feels uncomfortable. It is also the one that surfaces most often in due diligence conversations.

Summary

Running your own technical due diligence before investors do puts you in control of the narrative. You know your gaps, you can explain the trade-offs, and you can show the progress made. Work through the seven areas honestly. The gaps you find are almost always fixable — what you cannot fix is being caught off guard by them.