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Next.js 15 Performance: What Actually Moves the Needle
By Nima6 min read312 views
# Next.js 15 Performance: What Actually Moves the Needle
After working on performance optimization for dozens of Next.js applications, I've identified the changes that consistently make the biggest difference.
## 1. Server Components First
The single biggest performance win in Next.js 15 is fully embracing the Server Component model.
The rule is simple: **everything is a Server Component by default**. You only add `'use client'` when absolutely necessary.
```typescript
// ❌ Common mistake: making everything a client component
'use client'
import { db } from '@/lib/db'
export default function BlogList() {
// This forces all this logic to run on the client
}
// ✅ Correct: fetch data on the server
import { db } from '@/lib/db'
export default async function BlogList() {
const posts = await db.select().from(blogPosts)
return
{posts.map(p =>
}
```
## 2. Dynamic Imports for Heavy Components
Three.js, charts, rich text editors — these should never be in your initial bundle.
```typescript
const HeavyChart = dynamic(() => import('./HeavyChart'), {
ssr: false,
loading: () =>