<b>This week in caching: the stale-while-revalidate rabbit hole</b>

<b>This week in caching: the stale-while-revalidate rabbit hole</b>
Four pieces on serving slightly-old content so nobody waits on a cold cache:
— <i>RFC 5861 in plain English</i> — what stale-while-revalidate and stale-if-error actually promise, and which CDNs honor them.
— <i>SWR at the edge vs in SWR (the React hook)</i> — disambiguates the two things that share a name; skip if you already know the difference.
— <i>Async revalidation gotchas</i> — the thundering-herd problem when 10k users all trigger the background refresh at once, and request coalescing as the fix.
— <i>Browser-side: Cache-Control with stale-while-revalidate</i> — Chromium support notes for the response header version.
Credits: Harry Roberts and the Fastly docs team.
Bookmark: the request-coalescing piece — it's the part most SWR tutorials quietly skip.