Founders, fractional CTOs, investors, and diligence consultants

Software due diligence repo review playbook

Technical due diligence should connect codebase facts to decision risk. The output is not a scanner dump; it is a short memo that says what can be trusted, what needs containment, and what changes the plan.

Step 1

Define the diligence decision

The same repository can be reviewed for investment, acquisition, vendor risk, rescue work, or roadmap planning. The decision changes the evidence threshold.

Decision owner and deadline
Systems and repositories in scope
Critical product flows and revenue dependencies
Access gaps and assumptions

Step 2

Check delivery reality

A product that works in demo can still be risky if nobody can build, test, deploy, or recover it reliably.

Build and test commands
CI pipeline and deployment target
Rollback, backup, and migration process
Environment variable and onboarding documentation

Step 3

Review security and dependencies

Diligence should find the security problems that affect deal terms, immediate remediation, or operational readiness.

Committed secrets and token handling
Vulnerable dependencies and upgrade blockers
Auth, permission, and tenant-isolation boundaries
Audit logging and incident visibility

Step 4

Write the decision memo

The final memo should separate ordinary engineering debt from risks that change the business decision.

Go, no-go, or conditional-go recommendation
Top risks with evidence paths
First 30 days of remediation
Questions requiring owner or team follow-up

How to use this playbook

Before the review

Use this playbook to set scope before anyone starts fixing code. For founders, fractional ctos, investors, and diligence consultants, the first win is making the review explicit: what repository is in scope, what decision the work supports, and which access gaps still prevent a confident recommendation.

During the audit

Start with "define the diligence decision" and keep notes tied to files, routes, jobs, dependencies, or configuration. A useful audit does not say "the repo feels risky"; it shows the evidence path and explains why that evidence changes priority, estimate, or owner confidence.

After the readout

Use "write the decision memo" as the handoff point. Findings should become a small plan with owners, acceptance criteria, and a clear split between urgent containment, scheduled cleanup, and risk the team intentionally accepts for now.

What CodeTruss should produce

Run CodeTruss when the manual checklist needs to become repeatable: architecture map, health scores, source-backed findings, shareable report, GitHub issues, and optional fix PRs. The point is to shorten discovery while keeping the final decision evidence-based.

When the playbook is complete

Stop when the next decision is clear. A finished playbook should say whether to proceed, pause, contain risk, create issues, or gather missing access. It should not expand into open-ended cleanup. The output is a narrow, evidence-backed path to action.

What to re-check later

Revisit the playbook after the next scan, release, or cleanup batch. If the same risk appears again, the team needs a process change, not another one-off note.

Evidence to collect

Repository map and external dependency inventory
Build/test/deploy evidence and failure notes
Security and dependency findings with affected files
Conditional-go remediation list

Mistakes to avoid

Treating diligence as a style review
Ignoring deployment and data operations because they are outside product code
Failing to distinguish critical risk from normal startup mess
Publishing conclusions without evidence paths

Related guides

Sources and standards

Run this playbook on a real repository

CodeTruss builds the architecture map, health scores, ranked findings, report, GitHub issues, and opt-in fix PRs from the repository itself.

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