Fern, a multi-tenant documentation platform, uses Vercel and Next.js to achieve efficient multi-tenancy, faster development cycles, and significantly improved load times. By running on Vercel's infrastructure, Fern benefits from automatic caching, optimized content delivery, and instant scalability, which has driven a 50-80% reduction in page load times. The platform's architecture is built around a single Next.js app running on Vercel, handling multi-tenant routing across various customer domains. With Vercel's custom domain support, Fern supports both subdomains and subpaths, enabling customers to bring their own domains with just a CNAME DNS record. Fern also leverages Vercel Functions for rapid iteration, cutting deploy times down to five minutes and gaining the ability to test changes in preview environments before shipping to production. Additionally, Vercel's monorepo support allows Fern to deploy updates across all customer sites in minutes without managing infrastructure overhead. The platform has achieved enterprise-grade performance with fast-loading documentation, reduced latency through global content delivery, and automatic caching and Incremental Static Regeneration. Fern recently migrated 65% of its platform from Pages Router to Next.js App Router, unlocking major performance gains. With 63% month-over-month growth, Fern is rapidly scaling to serve customers worldwide, delivering a high-performance, multi-tenant documentation experience without the complexity of managing traditional infrastructure.