Monorepo with Turborepo: Scale Your Startup Codebase 2026

# Create new monorepo
mkdir my-startup && cd my-startup

# Initialize
npm init -w

# Install turbo
npm install -D turbo

# Create turbo.json
echo '{"pipeline": {"build": {}, "dev": {}, "lint": {}}}' > turbo.json

{
  "name": "my-startup",
  "private": true,
  "workspaces": [
    "apps/*",
    "packages/*"
  ],
  "scripts": {
    "build": "turbo run build",
    "dev": "turbo run dev",
    "lint": "turbo run lint"
  }
}

// apps/web/package.json
{
  "name": "@my-startup/web",
  "version": "0.0.0",
  "private": true,
  "scripts": {
    "dev": "next dev",
    "build": "next build",
    "lint": "next lint"
  },
  "dependencies": {
    "@my-startup/ui": "*",
    "@my-startup/utils": "*",
    "next": "latest",
    "react": "latest"
  }
}

// turbo.json
{
  "$schema": "https://turbo.build/schema.json",
  "pipeline": {
    "build": {
      "dependsOn": ["^build"],
      "outputs": [".next/**", "!.next/cache/**", "dist/**"]
    },
    "dev": {
      "cache": false,
      "persistent": true
    },
    "lint": {
      "dependsOn": ["^build"]
    },
    "test": {
      "dependsOn": ["^build"],
      "outputs": ["coverage/**"]
    },
    "deploy": {
      "dependsOn": ["build"],
      "cache": false
    }
  }
}

// packages/utils/src/index.ts
export function formatDate(date: Date): string {
  return new Intl.DateTimeFormat('en-US', {
    year: 'numeric',
    month: 'long',
    day: 'numeric'
  }).format(date)
}

export function cn(...classes: (string | undefined | null | false)[]): string {
  return classes.filter(Boolean).join(' ')
}

export function truncate(str: string, length: number): string {
  if (str.length <= length) return str
  return str.slice(0, length) + '...'
}

// packages/utils/package.json
{
  "name": "@my-startup/utils",
  "version": "0.0.0",
  "main": "./src/index.ts",
  "types": "./src/index.ts",
  "exports": {
    ".": "./src/index.ts",
    "./date": "./src/date.ts",
    "./string": "./src/string.ts"
  }
}

// packages/ui/src/Button.tsx
import { cn } from '@my-startup/utils'

interface ButtonProps extends React.ButtonHTMLAttributes<HTMLButtonElement> {
  variant?: 'primary' | 'secondary' | 'ghost'
}

export function Button({ 
  variant = 'primary', 
  className,
  children,
  ...props 
}: ButtonProps) {
  return (
    <button 
      className={cn(
        'px-4 py-2 rounded-lg font-medium transition-colors',
        variant === 'primary' && 'bg-blue-600 text-white hover:bg-blue-700',
        variant === 'secondary' && 'bg-gray-100 text-gray-900 hover:bg-gray-200',
        variant === 'ghost' && 'bg-transparent hover:bg-gray-100',
        className
      )}
      {...props}
    >
      {children}
    </button>
  )
}

// apps/web/app/page.tsx
import { Button } from '@my-startup/ui'
import { formatDate, cn } from '@my-startup/utils'

export default function HomePage() {
  return (
    <div className={cn('p-8', 'max-w-2xl')}>
      <h1 className="text-3xl font-bold">
        Welcome {formatDate(new Date())}
      </h1>
      
      <Button variant="primary" onClick={() => console.log('clicked')}>
        Get Started
      </Button>
    </div>
  )
}

// turbo.json - enable remote caching
{
  "pipeline": {
    "build": {
      "dependsOn": ["^build"],
      "outputs": ["dist/**", ".next/**"],
      "cache": true
    }
  }
}

# Login to Vercel for remote cache (optional)
npx turbo login
npx turbo link

# Run multiple apps in parallel
turbo run dev --parallel

# Run specific app
turbo run dev --filter=web

# Run all except mobile
turbo run dev --filter=!mobile

// root package.json
{
  "scripts": {
    "build": "turbo run build",
    "dev": "turbo run dev --parallel",
    "lint": "turbo run lint",
    "test": "turbo run test",
    "clean": "turbo run clean",
    "typecheck": "turbo run typecheck"
  }
}

// packages/types/src/api.ts
export interface User {
  id: string
  email: string
  name: string
  createdAt: string
}

export interface CreateUserInput {
  email: string
  name: string
  password: string
}

export interface ApiResponse<T> {
  data?: T
  error?: string
}

// Use in API (apps/api/src/routes/users.ts)
import { User, CreateUserInput, ApiResponse } from '@my-startup/types'

export async function createUser(input: CreateUserInput): Promise<ApiResponse<User>> {
  // Implementation
}

// Use in Web (apps/web/app/users/page.tsx)
import { User, ApiResponse } from '@my-startup/types'

// Full type safety across apps!

# .github/workflows/deploy.yml
name: Deploy

on:
  push:
    branches: [main]

jobs:
  deploy-web:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
      - run: npm install
      - run: npm run build
        working-directory: apps/web
      - uses: amondnet/vercel-action@v25
        with:
          vercel-token: ${{ secrets.VERCEL_TOKEN }}
          vercel-org-id: ${{ secrets.VERCEL_ORG_ID }}
          vercel-project-id: ${{ secrets.VERCEL_PROJECT_ID }}
          vercel-args: '--prod'
          working-directory: apps/web

# Each tiny utility in its own package
packages/
  utils/
    date/
    string/
    array/
    object/
    number/
# Result: Over-engineered, slow installs

# Group related code
packages/
  utils/        # All utilities
  ui/           # All UI components
  config/       # All configs
# Start simple, extract when needed

# Rebuild everything for small change
npm run build

# Rebuild only affected apps
turbo run build --filter=web