Scripts and Commands

package.json Scripts

{
  "name": "shopease",
  "scripts": {
    "dev": "next dev --turbopack",
    "build": "next build",
    "start": "next start",
    "lint": "eslint"
  },
  "dependencies": {
    "next": "15.5.4",
    "react": "19.1.0",
    "react-dom": "19.1.0"
  }
}

Command	What it does
`npm run dev`	Development server with Fast Refresh. Slower pages, helpful errors.
`npm run build`	Production build into `.next/`: compiles, type-checks, pre-renders static pages.
`npm run start`	Runs the production build (after `build`).
`npm run lint`	Runs ESLint with Next.js rules.

Reading the Build Output

Example

next build prints every route and how it is rendered. Learn to read this table; interviewers ask about it.

npm run build

Example output

   ▲ Next.js 15.5.4

   Creating an optimized production build ...
 ✓ Compiled successfully in 6.0s
 ✓ Linting and checking validity of types
 ✓ Generating static pages (6/6)

Route (app)                         Size  First Load JS
┌ ○ /                              1.2 kB         103 kB
├ ○ /about                           152 B         102 kB
├ ƒ /cart                          2.4 kB         105 kB
└ ● /products/[id]                   890 B         103 kB
    ├ /products/1
    └ /products/2

○  (Static)   prerendered as static content
●  (SSG)      prerendered as static HTML (uses generateStaticParams)
ƒ  (Dynamic)  server-rendered on demand

Production Run

Example

npm run build && npm run start

Example output

   ▲ Next.js 15.5.4
   - Local:        http://localhost:3000
 ✓ Ready in 320ms

Tip: Never deploy next dev. Always build then start (or use the Docker/standalone setup from the Advance level).