🧠 Engineering Culture

Product-Market Fit: 25 Ironclad Signs It's Real – Plus the Checklist VCs Demand

Retention flat at week 4? Users ghosting? That's no PMF. Here's the hard data and checklist to know for sure – before you scale into oblivion.

DevTools Feed Apr 03, 2026 4 min read

⚡ Key Takeaways

Hit 40% on Sean Ellis survey for PMF green light — test active users only.
Week-4 retention flattening trumps all surveys; it's the ultimate behavior test.
PMF spectrum: Nail one segment, expand. Organic growth confirms it.

Published by

Ship faster. Build smarter.

#pmf-checklist #product-market-fit #sean-ellis #startup-metrics

Get the best Developer Tools stories of the week in your inbox — no noise, no spam.

Originally reported by dev.to