Next.js Core (App Router)

• Server Components by default; minimal

  "use client"

  .
• Mutations in Server Actions (validate/authz; revalidate tags/paths).
• Route handlers for APIs/webhooks; add loading/error boundaries.

• ❌ Fetch initial data in

  useEffect

  .
• ❌ Cache or revalidate too broadly.
• ❌ Client-only authz.

references/