Prompts
Server components, caching, and the App Router mistakes generic advice misses
A lot of "Next.js" advice online is really just React advice with a different import path. The App Router era introduced genuinely new concepts — server components, caching semantics, streaming — that generic React knowledge does not cover.
Last updated Aug 15 · 12 min read
The App Router concepts generic React advice does not cover
Server components, the caching model, and streaming are genuinely new concepts the App Router introduced — not just React with different file conventions. The Next.js prompt library is written specifically for those concepts, the places where advice written for classic React (or the old Pages Router) actively misleads rather than just being outdated.
Server vs client: the boundary that determines everything else
Getting the server/client component boundary wrong is the single most common App Router mistake — putting 'use client' too high in the tree, or fetching data client-side that should have been a server component from the start. Auditing that boundary directly catches this. A related, newer trap: the "use cache" directive in Cache Components has specific rules about what can and cannot be cached, and auditing for that specific trap catches violations before they cause a confusing runtime error.
Caching strategy: ISR, forced dynamic rendering, and revalidation
Choosing the right ISR revalidation strategy — covered here — decides how stale content can get before regenerating. And a page that should be statically generated but silently isn't, because of a hidden dynamic API call somewhere in its tree, is diagnosed by this specific prompt — a class of bug that is invisible until you specifically know to look for it.
Route handlers, server actions, and middleware
Designing a real REST-style API with Route Handlers — this prompt — and building form validation into a Server Action — covered here — are two of the most common App Router backend patterns. Middleware specifically needs a latency budget in mind, since it runs on every matched request — an auth-guard middleware prompt addresses that constraint directly rather than treating middleware as a free lunch.
Performance: images, fonts, and eliminating waterfalls
An audit of next/image usage against Core Web Vitals catches the most common image-performance mistakes before Lighthouse does. Setting up next/font correctly avoids layout shift from web fonts. And parallel data fetching to eliminate waterfalls fixes the specific, common mistake of sequential awaits that should have run concurrently.
SEO and structured data, done the App Router way
Wiring up generateMetadata so every page actually gets dynamic SEO tags — this specific prompt — is the App Router-native way to handle metadata, replacing the old static meta tags approach entirely. Pair the resulting pages with the Schema Markup Generator for structured data on top of correctly generated metadata.
Migration, monorepos, and deployment
A real migration plan from the Pages Router to the App Router — this prompt — sequences the change rather than attempting it in one enormous pass. A Turborepo monorepo with shared packages has its own layout considerations, covered here, and self-hosting via a standalone Docker deployment — this prompt — matters for teams not deploying to a managed platform.
When an App Router build needs real engineering
These prompts sharpen individual decisions. A full production Next.js build — with the auth, testing and deployment architecture that decision requires holistically — is real engineering work. That's exactly what Scult's software team builds, or book a meeting to talk through your project.
Need this built into your business?
The free tools and prompts on this site handle the small, solved problems. If what you need is bigger — custom software, built and maintained for you — that's Scult's day job.
