How I Structure Large Next.js Projects — Folder Architecture Guide

Bad nextjs folder structure does not show up on day one. It shows up at month six when three developers search for the checkout form hook and find four copies. I reorganised a client dashboard after exactly that — this guide is the tree I use now on large App Router projects, why each folder exists, mistakes from my first Next.js apps, and the 10-second findability rule. Real folder tree — production-shaped layout my-app/ Routes live in app/. Business logic lives in features/. Generic design sys