AI computer-vision software that reads commercial HVAC (heating, ventilation, and air conditioning) blueprints to auto-generate bills of materials and quotes for equipment distributors and rep firms, having doubled annual recurring revenue (ARR) in the first six weeks of 2026.

Founder-led, insider-network motion inside a narrow B2B vertical, propped up by always-on paid search that generates demand in an unbranded, low-search category rather than any public-facing content or social engine.

A $14M Series A closed March 2026, ~40 enterprise clients as of that announcement (seven of whom are also investors), an estimated low-to-mid seven-figure ARR run rate (not publicly disclosed, inferred from the raise and client count), and 4 Google ads still active as of 2026-07-16, the oldest running 111 days.

Rebar's real distribution asset is not content or social, it is turning its own earliest customers into its cap table, a mechanic that only works because commercial HVAC distribution is a small, relationship-dense buyer universe where a happy customer's opinion travels fast.