Feature-Based React Architecture That Actually Scales

A deep dive into building a scalable React 19 enterprise app using feature-based architecture, TanStack Query, Zod with i18n, and a strict service layer pattern. Introduction I've been building FlowBoard — a full-featured React SPA for team collaboration, project tracking, and workflow management. After months of iteration, the codebase has grown to 350+ source files across 8 feature modules , supporting 4 languages , with a clean architecture that hasn't slowed me down. In this article, I'll break down the architecture decisions, folder structure, and patterns that keep this codebase maintainable at scale. Whether you're starting a new project or refactoring an existing one, these patterns can help. Tech Stack at a Glance: Layer Technology Framework React 19 + TypeScript 5.9 Build Vite 7 UI Radix UI + shadcn/ui + Tailwind CSS v4 Server State TanStack Query v5 Tables TanStack Table v8 Forms React Hook Form + Zod Routing React Router 7 HTTP Axios (interceptors + token refresh) i18n reac