Inside Linear's Speed: Engineering a Local-First, Zero-Spinner UI

This technical breakdown reveals how Linear achieves native-feeling speed without exotic infrastructure. The key is a local-first architecture where the browser's IndexedDB acts as the primary database, mutations apply optimistically to an in-memory MobX store, and a custom sync engine flushes changes asynchronously. Combined with a deliberately simple stack—React, TypeScript, Postgres, and a CDN—and aggressive first-load optimizations, the app hides network latency entirely. The author distills these techniques into actionable lessons any web developer can adopt, from optimistic UI patterns to eliminating unnecessary loading states.