Project layout

The src/ tree, composition roots, and where to put code on different frameworks.

DMA isn't tied to one framework. The rules are the same; only the composition root folder name changes — where routes and layout mount modules.

Base tree

src/
├── app/         # composition root (Next.js App Router, Vite+React)
├── features/    # leaf modules
├── services/    # appears on promotion — don't create upfront
└── shared/
    ├── ui/
    ├── lib/
    ├── api/
    ├── model/
    └── domain/  # optional

Composition roots

Under src/, any of these folders is the same layer by DMA rules:

Folder	Typical framework
`app/`	Next.js App Router, Vite + React
`pages/`	Astro, classic Next pages
`routes/`	TanStack Router, SvelteKit

All of them:

mount modules through */public/*;
are not imported by modules;
keep routes thin — import from public/, minimal logic.

// src/app/checkout/page.tsx
import { CheckoutPage } from "@/features/checkout/public/checkout-page";

export default function Page() {
  return <CheckoutPage />;
}

If the project has multiple roots, prefer app/. Tooling picks app first on conflict.

Where to put what

You have…	Put it in…
Route, layout, providers	Composition root
Screen / user flow	`features/<name>/public/` or stage-0 file
State for one feature	Inside the feature, next to the consumer
Logic needed by other modules (product)	`services/<name>/public/`
Portable UI / helpers	`shared/ui/`, `shared/lib/`
Base HTTP client, interceptors	`shared/api/`
Endpoints for one feature	Inside the feature (`*.api.ts`)
Wiring features / events	Composition root — props, providers, ports
Unit tests	Next to the file (`*.test.ts`)

Examples by framework

The DMA repo has five clean examples with one product story (catalog, checkout, cart):

Example	Composition root	Stack
vite-react	`src/app/`	Vite + React
next-app	`src/app/`	Next.js
astro-pages	`src/pages/`	Astro
sveltekit-routes	`src/routes/`	SvelteKit
vue-vite	`src/app/`	Vue 3 + Vite

Easiest to start with vite-react — runnable, with tests and the full module stage ladder.

Module stage ladder

Stage 0   features/profile.tsx
Stage 1   features/checkout/public/ + internals
Promotion services/cart/public/     ← catalog + checkout import
Lift      shared/lib/format-currency.ts  ← 2+ modules, no product logic

More — Modules & public API and Code evolution.