Request waterfall flattened; critical path under 3 hops

A request waterfall where API B cannot start until API A completes means your page load time is the sum of all sequential fetch durations, not the maximum. A five-hop waterfall with 200ms fetches adds 1 full second of latency that cannot be improved by any infrastructure optimization — it is a code architecture problem. ISO 25010:2011 time-behaviour formalizes the concern; the user-facing result is a page that appears slow even on fast connections because the CPU is idle while waiting for chained network calls to resolve.

Replace sequential await chains with Promise.all for independent fetches. In Next.js Server Components, initiate fetches without await at the top of the component to enable parallel execution.

// app/dashboard/page.tsx — parallel fetches
export default async function DashboardPage() {
  // Start all three fetches simultaneously
  const [user, orders, stats] = await Promise.all([
    fetchUser(),
    fetchOrders(),
    fetchStats(),
  ])
  // ...
}