Building Scalable APIs with Next.js Route Handlers

Building APIs that scale isn't just about handling more requests — it's about designing systems that remain maintainable, testable, and reliable as your application grows. In this post, I'll walk through the patterns I use when building production APIs with Next.js Route Handlers.

Next.js App Router introduced Route Handlers as a first-class way to build API endpoints. They offer several advantages over the legacy API routes: