Signal definition
Engineering Hiring Burst
Strong indicator that a startup recently closed a round and is deploying capital into engineering. For investors: probably too late for the current round, well-positioned for the next one.
Unit: binary signal (fires / does not fire) · Window: 6-week window
Formula
fires if contributor-growth ≥50% AND distinct_authors ≥3 AND no commits-from-new-author in prior 60 daysDecision rule
Single firing per org per quarter; debounced so a continuous hiring ramp does not fire repeatedly.
Common pitfall
An open-source project that suddenly gets popular can fire this without a fundraise. We attempt to filter by org-vs-project signals (private repo presence, .vercel.json, deploy automation), but the heuristic is imperfect.
Related signals
Defined in the SSRN-indexed methodology paper. Full definition, assumptions, and validation in §3 of the paper. Reproducibility kit at /reproducibility. Glossary entry at /glossary#engineering-hiring-burst.
Five breakout startups, every Sunday, before the round gets crowded
The free Acceleration Watch: five venture-backed teams accelerating on the engineering signal, translated into plain English, 21 to 47 days before the deck circulates. No code-reading, no card.