How to Fix Client-Server Waterfalls When Migrating from Vite to Next.js

Migrating a production app from Vite to Next.js is a common scaling decision, but developers often introduce a hidden performance problem called a client-server waterfall by carrying over patterns like useEffect and useQuery hooks. This occurs when the server sends a partially rendered page and the client must still make sequential API requests, causing layout shifts and slow Time to Interactive. The recommended fix is to fetch data directly inside Next.js Server Components, which resolve data during server-side rendering before any HTML reaches the browser. When multiple data sources are needed, using Promise.all instead of sequential awaits ensures requests run in parallel, reducing total load time to that of the slowest single request. Next.js Suspense boundaries can further improve perceived performance by streaming fast page sections immediately while slower components load in the background.