BigBinary Blog 2026-03-08T07:02:52+00:00 https://www.bigbinary.com/ <![CDATA[CDN caching issue involving Cloudfront and Cloudflare]]> Unnikrishnan KP 2026-02-02T12:00:00+00:00 https://www.bigbinary.com/blog/cdn-caching-issue-involving-cloudfront-and-cloudflare Recently, some Neeto customers reported experiencing a verylong page load time. For some of them, the page didn't even load. We found thatthe issue is related to CDN caching.

Neeto uses React.js for the front-end code, and the asset files are hosted atCloudFront. To complicate matters, we use CloudFlare as our DNS resolver.Between CloudFlare and Cloudfront, we were not sure what was being cached and atwhat level. Since this problem was being faced only by our customers, it was abit difficult to reproduce and debug.

The whole setup is like this:

  • Browsers make requests to https://cdn.neetox.com/assets/xyz.js
  • Clouflare forwards the request to Cloudfront
  • CloudFront acting as the caching layer will try to get the data from theNeetoDeploy server and will cache the result

If the browser is not getting the requested file, then in this chain, something didn'twork correctly.

During the investigation, we found that Cloudflare was being a bit mischievousand was doing things it should not be doing. Watch the video to see what I mean.

The video mentioned below is the one I created for the internal Neeto folks. Thevideo is being published as-is without any modifications.

<iframewidth="560"height="315"src="https://www.youtube.com/embed/_TCU14fN08A?si=Xy_o6cpSjGvsFFCm"title="CDN caching issue involving Cloudfront and Cloudflare"frameborder="0"allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share"referrerpolicy="strict-origin-when-cross-origin"allowfullscreen

</iframe>

You can see the transcript of the videohere.

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