I built the entire platform's engineering: the backend, the AI pipeline that reads drawings and generates structured materials lists, the full commercial workflow (quotes, orders, invoicing, and a wholesaler-contractor marketplace with broadcast RFQs where suppliers bid and first-to-accept wins), tiered Stripe billing with per-drawing metering, campaign codes and trials, every third-party integration (accounting, chat/email notifications, Google/Microsoft SSO, e-signing, shipping, company-number lookup), plus projects with a shared team chat, external-participant invites, and the production infrastructure.