# Server-Side Rendering

For applications that need personalized data, authentication, or real-time updates, Neutron provides Server-Side Rendering (SSR).

## The Request Lifecycle

When a request hits an App Route:

1.  **Request**: The server receives the HTTP request.
2.  **Middleware**: Global and route-specific middleware run.
3.  **Routing**: The router matches the URL to a set of components (Layouts + Page).
4.  **Loaders**: All matching loaders run in **parallel** to fetch data.
5.  **Render**: The component tree is rendered to HTML strings, injected with the loader data.
6.  **Response**: The HTML is streamed to the browser.
7.  **Hydration**: The browser loads the client-side JavaScript, and Preact "hydrates" the HTML to make it interactive.

## Why SSR?

-   **SEO**: Search engines see the fully rendered content.
-   **Performance**: Users see content sooner than with Client-Side Rendering (CSR), as they don't have to wait for the JS bundle to download and execute before seeing the page.
-   **Robustness**: Works gracefully on slow networks/devices.

## Caching

Unlike static routes, SSR routes are rendered on every request. To improve performance, you can use standard HTTP `Cache-Control` headers.

```tsx
export function headers() {
  return {
    "Cache-Control": "public, max-age=60, s-maxage=3600",
  };
}
```