Optimising Caching on Pwned Passwords (with Workers)

What this post added

This post details how Cloudflare Workers and custom cache key configurations were used to optimize the caching for the Pwned Passwords API, significantly improving its cache hit ratio. Specifically, it addresses two key issues: 1. Normalizing the case of the hash prefix in API requests to ensure consistent caching. 2. Removing the 'Origin' header from the cache key to prevent duplicate caching of the same asset from different origins. The post also touches upon the role of Argo in providing tiered caching.