Build and own the frontend for a company intelligence and verification platform, including a Next.js customer dashboard, scalable SEO-focused company profile pages, and a Mintlify developer documentation portal. Implement authentication, billing, API key management, alerts, watchlists, eSign flows, data-dense interfaces, email templates, and performance optimizations. Work independently from written design briefs while prioritizing correctness, speed, accessibility, and reliable loading, empty, and error states.