Cloudflare Workers – the workhorse at the edge

Cloudflare Workers provides Function-as-a-Service (FaaS) at the edge of its network. Workers was introduced in 2017 September as beta and opened up to everyone in 2018 March. Adding programming capabilities to a cache is nothing new. Multiple open source projects support adding programmability to a caching or edge server. The varnish cache (https://varnish-cache.org/) provides a configuration language called varnish configuration language (VCL). Similarly, Nginx supports adding LUA programs as modules (https://www.nginx.com/resources/wiki/modules/lua/), as do many other projects, including HAProxy, Kong API Gateway, and others. All these services aim to achieve one thing: intercept the HTTP requests and responses at the edge and modify them with custom logic for better performance and/or additional feature support.

Cloudflare and other CDN/edge service providers use different tools and services to keep adding features at the...