The cacheability problem you can't fix at request time
A CDN cache and an origin server work as a pair. Their goal is to answer from the cache whenever possible and only go back to the origin when the edge can't respond. The origin guides the cache. When it returns a cacheable asset, the response headers tell Cloudflare how long it's OK to serve, when and how to revalidate, and even whether to cache it at all. The cache is only as efficient as the origin allows. If the origin gets it wrong, the cache becomes decoration and origin infrastructure costs skyrocket.
Most cache eligibility problems are not decided at request time. They manifest after the origin replies. A visitor asks for an asset. Cloudflare checks cache, it misses, and forwards the request to the origin. The origin returns the file. Somewhere in those response headers, quietly, is a header that says "don't cache this." The asset that should have been cached at every Cloudflare data center is now uncacheable. Multiply that by every visitor, on every site, with the same accidental header, and you have a cache hit ratio that is leaking origin bandwidth, ruining performance, and driving infrastructure costs higher.
The familiar failure modes
The list of ways this goes wrong is long. The origin sends Cache-Control: no-store on assets that are perfectly safe to cache on the CDN. The origin sends correct directives, but they're meant for the browser, not for Cloudflare. The origin attaches an ETag that's overly aggressive and causes revalidation thrash on every conditional request. The list goes on. In large teams, the people managing the origin's responses and the group that manages the CDN are often different, which makes changing a one-line header a weeks-long negotiation.
None of these problems can be solved at request time. By the time Cloudflare sees the header on the response, the request phase is over. The response is already in flight.
Cache Response Rules run at the right moment
Cache Response Rules run after the origin's response arrives at Cloudflare but before it gets written to cache. With them, you can rewrite directives, manage cache-tags, and strip headers like Set-Cookie, Authorization, and Cache-Control from the origin response before Cloudflare's cache ever sees them. The fix lives entirely on Cloudflare. No origin code changes required.
This is the right place to fix these problems, and until now there was no clean way to do it. The Cloudflare cache control surface has been evolving for years, and Cache Response Rules are the next step. They handle the cases that page rules and configuration changes can't reach, and they handle them in a way that doesn't require coordinating with the team that owns the origin.
Why this is a real product, not a feature
The cache hit ratio is one of the most economically meaningful metrics for any large site. Every percentage point of hit ratio is bandwidth you don't pay for, latency you don't incur, and origin capacity you don't have to provision. The cost of a broken cache is not abstract. It shows up in the AWS bill or the Cloudflare Workers bill or the origin team's on-call burden.
The features that move the hit ratio needle are usually the features that don't make the front page. Cache Response Rules are a feature in that tradition. They aren't a product launch in the way a new AI service is. They are a fix for a class of problems that have been quietly costing real money, and the fix lives in the right place in the stack.