Engineering Due Diligence for Angel Investors: A Framework
A practical framework for angel investors conducting engineering due diligence on startups. What to check on GitHub, what questions to ask founders, and how to evaluate technical risk without being an engineer.
Key Takeaway
Angel investors often lack the technical background to evaluate a startup's engineering team. This framework bridges the gap: five public GitHub signals to check before a meeting, five questions to ask founders during the call, and red flags that indicate technical risk. The approach does not require coding skills — it requires knowing what patterns to look for. Commit velocity change (+50%+ is strong), contributor growth (recent hires confirm team scaling), infrastructure buildout (new repos signal platform maturity), and tech stack consistency (does GitHub match the pitch?) are all checkable in under 10 minutes.
Angel investors make decisions with less information than institutional VCs. You often meet a founder once, review the deck, and decide whether to write a check. Engineering due diligence — if you do it at all — is a back-of-the-envelope exercise.
Public GitHub data changes this. You can evaluate a startup's engineering health in 10 minutes, without being a developer yourself. Here is the framework.
Before the Meeting: Five GitHub Checks
**1. Check commit velocity change.** Open the startup's profile on VC Deal Flow Signal. Is their 14-day commit velocity positive and above +50%? That is strong engineering momentum. Negative or flat velocity across two consecutive windows is a potential red flag.
**2. Review their GitHub organization.** How many public repositories are active? What languages and frameworks appear? A startup claiming to build an AI platform should show Python, ML frameworks. A fintech startup should show security-related tooling. If the GitHub activity does not match the pitch, ask why.
**3. Look at contributor diversity.** A startup with 20 employees but only 1 GitHub contributor likely has most code in private repos (normal for some sectors) or overstates the engineering team size. Both are worth understanding.
**4. Check for infrastructure buildout.** Three or more new repositories in 30 days is a positive signal — the team is building platform infrastructure. Zero new repos in six months may indicate stagnation.
**5. Review the commit history pattern.** Consistent daily commits suggest disciplined engineering. Erratic patterns — long silences followed by frantic bursts — may indicate project-based work rather than product development.
For the full metrics framework, read the 7 engineering metrics every investor should track.
During the Meeting: Five Questions
These questions do not require technical depth. They reveal engineering maturity:
- "How do you decide what to build next?" — Product-led or roadmap-led? Customer feedback-driven or founder intuition?
- "What is your deploy frequency?" — Daily vs. monthly tells you about CI/CD maturity.
- "How do you handle technical debt?" — The answer reveals long-term thinking.
- "What is the team structure?" — Flat vs. hierarchical reveals communication patterns.
- "What is your testing approach?" — Automated testing signals engineering discipline.
Red Flags
- Single contributor at a company claiming a team of 10+ - Zero public GitHub activity for a technical product - Tech stack mismatch with product description (Python claimed but only JavaScript in repos) - Long commit gaps (2+ months of silence) - Consistent velocity decline across two tracking windows
Browse the sector rankings to see how companies compare on engineering health, or read the investor mistakes to avoid when interpreting this data.