Building Modern Web Applications with Next.js 15

Next.js 15 brings significant improvements to web development with enhanced performance, better developer experience, and powerful new features that make building production applications easier than ever.

What's New in Next.js 15?

Next.js has evolved significantly with version 15, focusing on stability, performance, and developer experience. The App Router is now production-ready, React Server Components are the default, and Turbopack provides lightning-fast development builds.

Key Features

1. Stable App Router

The App Router, built on React Server Components, is now fully stable and production-ready. It offers intuitive file-system routing with automatic code splitting and built-in loading and error states.

2. React Server Components by Default

Server Components render on the server by default, sending only HTML to the client. This dramatically reduces bundle sizes and improves initial page load times.

// app/dashboard/page.tsx
export default async function Dashboard() {
  const data = await fetchData() // Direct data fetching
  
  return (
    <div>
      <h1>Dashboard</h1>
      <DataTable data={data} />
    </div>
  )
}

Client Components are opt-in with the 'use client' directive, keeping your JavaScript bundle lean.

3. Turbopack for Fast Development

Turbopack, Vercel's Rust-based bundler, is stable in Next.js 15. It's up to 700% faster than Webpack, providing near-instant updates during development.

next dev --turbo

4. Enhanced Image Optimization

The Image component now has better automatic optimization, improved lazy loading, and support for modern formats like WebP and AVIF.

import Image from 'next/image'

<Image
  src="/hero.jpg"
  alt="Hero"
  width={1200}
  height={600}
  priority
  placeholder="blur"
/>

5. Partial Prerendering (Experimental)

Partial Prerendering combines static and dynamic rendering in the same route. Static parts are prerendered at build time while dynamic parts stream at runtime—the best of both worlds.

Getting Started

Create a new Next.js 15 project:

npx create-next-app@latest my-app

# Options:
# ✓ TypeScript
# ✓ ESLint  
# ✓ Tailwind CSS
# ✓ App Router
# ✓ Import alias (@/*)

Project Structure

app/
├── layout.tsx       # Root layout
├── page.tsx         # Home (/)
├── about/
│   └── page.tsx     # About (/about)
├── blog/
│   ├── page.tsx     # Blog index
│   └── [slug]/
│       └── page.tsx # Blog post
└── api/
    └── route.ts     # API route

Data Fetching Patterns

Server Components

async function getData() {
  const res = await fetch('https://api.example.com/data', {
    cache: 'force-cache' // Static
  })
  return res.json()
}

export default async function Page() {
  const data = await getData()
  return <div>{data.title}</div>
}

Client Components

'use client'
import { useState, useEffect } from 'react'

export default function ClientComponent() {
  const [data, setData] = useState(null)
  
  useEffect(() => {
    fetch('/api/data')
      .then(res => res.json())
      .then(setData)
  }, [])
  
  return <div>{data?.title}</div>
}

Performance Best Practices

Deployment

Next.js 15 apps deploy seamlessly to Vercel with zero configuration. Push to GitHub and connect to Vercel for automatic builds and deployments.

# Build for production
npm run build

# Start production server
npm start

Conclusion

Next.js 15 represents a major step forward in web development. With stable Server Components, Turbopack performance, and enhanced developer experience, it's the ideal framework for building modern web applications.

Whether you're building a simple blog or a complex SaaS platform, Next.js 15 provides the tools and patterns to create fast, scalable applications with confidence.