Next.js 14 App Router: 6 Months of Production Lessons

The Migration

Six months ago, we committed to App Router for all new Next.js projects. Here's what we learned.

The Wins

Server Components eliminated so much boilerplate. No more API routes for simple data fetches. Just async functions in your component.

Nested layouts are genuinely powerful once you internalize the mental model.

The Gotchas

Error boundaries work differently. useEffect re-runs more often than you'd expect. Client/Server boundaries require discipline.

Patterns That Stuck

• Collocate Client Components with their Server Component parents
• Use Server Actions for all form submissions
• Cache aggressively with revalidatePath()

These patterns are baked into every project we ship. See how they played out in our fintech platform rebuild — a PHP monolith migrated to Next.js App Router with zero downtime and a load time drop from 4.2s to 0.8s.