Feature-Sliced Design

Feature-Sliced Design structures large Next.js apps into seven layers—app, views, widgets, features, entities, and shared—to prevent circular dependencies. It enforces cross-layer import rules and a public API export pattern for scalable maintenance.

The best way to organize a Next.js monorepo using Turborepo is applying Feature-Sliced Design. It provides a monorepo-friendly structure with isolated app structures and shared packages, ensuring scalable front-end code maintenance across the workspace.

Feature-Sliced Design works with the Next.js App Router by mapping routing and app structure guidance to the FSD app layer. It separates concerns into slices and segments like ui, model, api, lib, and config within the seven-layer architecture.

You enforce public API rules in a Next.js project by applying the Feature-Sliced Design public API export pattern via index.ts files. This prevents unauthorized cross-imports between slices and layers, avoiding circular dependencies in the codebase.

You need Feature-Sliced Design for your frontend architecture when building large-scale Next.js applications in a Turborepo. It breaks concerns into layers to improve maintainability and prevent circular dependencies in complex monorepos.