From a6e1069e45152992cd420841cac543a966391a28 Mon Sep 17 00:00:00 2001
From: Josh <josh@macawls.dev>
Date: Fri, 9 Jan 2026 04:23:12 +0200
Subject: [PATCH] perf: optimize cache headers for CDN-first caching

Use s-maxage=86400 for Cloudflare edge caching (24h) with max-age=0
so browsers always fetch from CDN. Combined with existing cache purge
on content changes, this minimizes origin server load while ensuring
fresh content.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
---
 internal/server/blog.go | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/internal/server/blog.go b/internal/server/blog.go
index 8b873d5..13c528b 100644
--- a/internal/server/blog.go
+++ b/internal/server/blog.go
@@ -98,7 +98,7 @@ func (s *Server) blogHome(w http.ResponseWriter, r *http.Request) {
 	s.recordPageView(q, r, "/", "")
 
 	if html, etag, err := q.GetPage(r.Context(), "/"); err == nil && html != nil {
-		s.servePreRendered(w, r, html, etag, "public, max-age=300")
+		s.servePreRendered(w, r, html, etag, "public, s-maxage=86400, max-age=0")
 		return
 	}
 
@@ -156,7 +156,7 @@ func (s *Server) blogHome(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	s.servePreRendered(w, r, html, computeETag(html), "public, max-age=300")
+	s.servePreRendered(w, r, html, computeETag(html), "public, s-maxage=86400, max-age=0")
 }
 
 func (s *Server) blogList(w http.ResponseWriter, r *http.Request) {
@@ -172,7 +172,7 @@ func (s *Server) blogList(w http.ResponseWriter, r *http.Request) {
 	s.recordPageView(q, r, "/posts", "")
 
 	if html, etag, err := q.GetPage(r.Context(), "/posts"); err == nil && html != nil {
-		s.servePreRendered(w, r, html, etag, "public, max-age=300")
+		s.servePreRendered(w, r, html, etag, "public, s-maxage=86400, max-age=0")
 		return
 	}
 
@@ -223,7 +223,7 @@ func (s *Server) blogList(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	s.servePreRendered(w, r, html, computeETag(html), "public, max-age=300")
+	s.servePreRendered(w, r, html, computeETag(html), "public, s-maxage=86400, max-age=0")
 }
 
 func (s *Server) blogPost(w http.ResponseWriter, r *http.Request) {
@@ -249,7 +249,7 @@ func (s *Server) blogPost(w http.ResponseWriter, r *http.Request) {
 		s.recordPageView(q, r, path, slug)
 
 		if html, etag, err := q.GetPage(r.Context(), path); err == nil && html != nil {
-			s.servePreRendered(w, r, html, etag, "public, max-age=3600")
+			s.servePreRendered(w, r, html, etag, "public, s-maxage=86400, max-age=0")
 			return
 		}
 	}
@@ -457,7 +457,7 @@ func (s *Server) blogPost(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	s.servePreRendered(w, r, html, computeETag(html), "public, max-age=3600")
+	s.servePreRendered(w, r, html, computeETag(html), "public, s-maxage=86400, max-age=0")
 }
 
 func (s *Server) canPreview(r *http.Request, tenantID string) bool {
@@ -543,7 +543,7 @@ func (s *Server) sitemap(w http.ResponseWriter, r *http.Request) {
 	baseURL := getBaseURL(r.Host)
 
 	w.Header().Set("Content-Type", "application/xml; charset=utf-8")
-	w.Header().Set("Cache-Control", "public, max-age=3600")
+	w.Header().Set("Cache-Control", "public, s-maxage=86400, max-age=0")
 
 	w.Write([]byte(`<?xml version="1.0" encoding="UTF-8"?>
 <urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">