Note from 15 March 2022

TIL: #Cloudflare doesn't support the Vary HTTP header, which means the origin server can't do any content negotiation, for example send WebP or AVIF for a JPEG request…

#Fastly supports it, just saying… 😅

  1. screenshot of Caching Header Best Practices

    Simon Hearne avatar Simon Hearne

    Caching Header Best Practices

    Client-side caching is a key technique to improving front-end speed and user experience. Whilst it may appear complex and risky, investing the time to review your content and setting the correct response headers will reduce bandwidth utilisation and improve speed for return visitors as well as mid-session.

  2. screenshot of Performant A/B Testing with Cloudflare Workers

    Philip Walton avatar Philip Walton

    Performant A/B Testing with Cloudflare Workers

    The problem with the current A/B testing tools is they construct the test on the client. They block rendering until they can determine which experiment group the current user should be in, and then they update the DOM based on that experiment’s parameters. On slow connections or low-end devices, this can mean users are staring at a blank screen for seconds waiting for network requests to finish before rendering can even start.