Feature-Sliced Design (FSD) v2.1

Source: fsd.how | Strictness can be adjusted based on project scale and team context.

1. Core Philosophy & Layer Overview

FSD v2.1 core principle: "Start simple, extract when needed."

Place code in pages/ first. Duplication across pages is acceptable and does not automatically require extraction to a lower layer. Extract only when the team agrees it is necessary.

Not all layers are required. Most projects can start with only shared/, pages/, and app/. Add widgets/, features/, entities/ only when they provide clear value. Do not create empty layer folders "just in case."