I indexed 17,341 polynomial fan curves in Postgres and matched a duty point in <100ms

Most B2B HVAC catalogs publish fan performance curves as scanned PDFs. Engineers do the interpolation by eye when they need to know "will this fan deliver 5,000 m³/h at 350 Pa?" — they overlay the operating point on the curve image and squint. I wanted a catalog where the curves compute. Here's what that took. TL;DR I parsed 17,341 fan curves from manufacturer PDFs into 3rd-degree polynomial coefficients, stored them as JSONB arrays in Postgres, and built a selection engine that ranks all 17,341