Streaming Server-Side Rendering (SSR) with Pareto 4.0 introduces a significant performance and user experience improvement over traditional SSR methods, especially when dealing with complex web applications that fetch data from multiple sources or APIs.
Key Concepts
-
Separation of Fast and Slow Data:
- In the
loader.tsfile, you separate your data into two categories: fast (data that resolves quickly) and slow (data that takes longer to resolve). - The
deferfunction is used to wrap slow data in a Promise, allowing it to be streamed asynchronously.
- In the
-
Streaming SSR:
- Pareto sends the initial HTML immediately when using streaming SSR.
- Slow data streams in as it resolves, allowing for progressive rendering and better user experience during page load.
-
Client-Side Navigation:
- Client-side navigations also use NDJSON (newline-delimited JSON) streaming to deliver loader data progressively.
- This ensures that Suspense boundaries work identically on first load and client navigation, maintaining consistency in UX.
-
Performance Under Load:
- Streaming SSR allows the server to handle more concurrent requests efficiently by releasing rendering threads immediately after sending initial HTML.
Read the full article at DEV Community
Want to create content about this topic? Use Nemati AI tools to generate articles, social posts, and more.

![[AINews] The Unreasonable Effectiveness of Closing the Loop](/_next/image?url=https%3A%2F%2Fmedia.nemati.ai%2Fmedia%2Fblog%2Fimages%2Farticles%2F600e22851bc7453b.webp&w=3840&q=75)



