Next.js Architecture (FSD)

Feature-Sliced Design (FSD) is an architectural methodology that organizes Next.js applications by business domain slices, such as features and entities, and enforces a strict layer hierarchy to maintain scalability and reduce boilerplate.

Structure your scalable Next.js app by grouping code into business domain slices within the src directory. Apply the FSD layer hierarchy—App, Widgets, Features, Entities, and Shared—to separate concerns and integrate with Next.js App Router conventions.

Yes, Feature-Sliced Design integrates with Next.js App Router conventions. It aligns the strict layer hierarchy with App Router routing, server actions, and data access patterns to maintain a scalable project structure.

You should refactor to FSD when your Next.js application grows large and becomes difficult to manage. Applying this architecture prevents architectural decay by organizing code by business domain rather than file type.

Using FSD for Next.js architecture requires adhering to a strict layer hierarchy and segment naming conventions. This methodology introduces structural overhead that is best suited for large-scale applications rather than small, simple projects.

FSD is a robust approach for organizing Next.js folder structure if you need strict layer separation and business domain grouping. Compared to organizing by file type, it provides better maintainability and scalability for complex applications.