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PE/VC9 min read

5 Red Flags PE Firms Miss in Technical Due Diligence

PE firms lose millions because their due diligence stops at revenue metrics. Here are the 5 engineering signals that predict failure.

By Richard Ewing·

The Due Diligence Blind Spot

PE firms deployed over $800B in tech acquisitions in 2025. ~40% failed to meet their thesis within two years due to hidden engineering liabilities.

Red Flag #1: Maintenance Load Above 65%

Ask the CTO what percentage goes to maintenance vs. new features. If they don't know — that's a red flag. If it's above 65%, you're buying a company spending more on lights-on than value creation.

Red Flag #2: Single Points of Knowledge

Map the "bus factor" for every revenue-critical system. Any system with a bus factor of 1 needs immediate knowledge transfer planning.

Red Flag #3: Undocumented AI Costs

Many companies book AI costs as R&D without breaking them out. A company reporting 80% gross margins might actually have 60% when you properly allocate AI costs to COGS.

Red Flag #4: Deployment Frequency Below Weekly

A 50-person team deploying less than weekly signals fragile code, insufficient testing, or high coordination costs.

Red Flag #5: No Engineering Economic Model

If the CTO can't articulate decisions in economic terms, they're making capital allocation decisions without frameworks. Budget 6-12 months and $200-400K post-acquisition.


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Published Work

This article expands on ideas from my published work in CIO.com, Built In, Mind the Product, and HackerNoon. View published articles →

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Richard Ewing

The Product Economist — Quantifying engineering economics for technology leaders, PE firms, and boards.