Feature-Based-Layered-Architecture

Feature-based layered architecture in Next.js organizes applications into Handler, Service, Repository, and Adapter layers within domain-specific feature modules to enforce separation of concerns and improve scalability.

Structure Next.js API routes and domain logic by grouping functionality under a features/ directory, separating code into Handler, Service, Repository, and Adapter layers, and exposing public APIs via index.server.ts and index.client.ts files.

Yes, this architecture pattern works with Supabase and server-only directives. It integrates the @supabase/supabase-js dependency and enforces server-only directives to clearly separate client and server execution contexts.

The best way to organize a scalable Next.js App Router project by domain is using a feature-based module structure. This groups functionality by domain under features/ rather than by technical role, ensuring maintainability and clear public API exposure.

Use a four-layer separation in your Next.js application when you need strict boundaries between API routing, business logic, data access, and external integrations to prevent code entanglement and ensure long-term maintainability.