Prototyping optimizations with Cloudflare Workers and WebPageTest

What this post added

This post introduces a novel approach to prototyping and testing web performance optimizations by combining Cloudflare Workers and WebPageTest. It details how Cloudflare Workers can act as programmable proxies to intercept and modify requests and responses at the edge, and how WebPageTest's `overrideHost` command can redirect traffic through these workers. The post demonstrates practical use cases such as testing the performance benefits of single-connection loading, self-hosting third-party scripts using HTMLRewriter, request mangling with delays, and implementing custom HTTP/2 prioritization schemes. This significantly lowers the barrier to experimentation and innovation in web performance.