Deno is joining Cloudflare, where Ryan Dahl and Bert Belder will lead an effort to give developers a supported way to run Workers applications on infrastructure they host themselves. Cloudflare plans to incorporate code and ideas from celld, Deno’s implementation of Workers and Durable Objects, into its open-source runtime, workerd. Developers can already self-host either runtime, while Cloudflare says further details about the effort will follow over the coming months.
The work targets a concrete limitation for developers trying to run Workers applications outside Cloudflare: workerd’s Durable Objects support currently operates within a single instance and cannot scale. Cloudflare describes that implementation as sufficient for local testing, despite having released workerd for production use. The planned effort aims to make self-hosting a fully supported option for applications using the Workers programming model.
Read more: Cloudflare Makes Python Workers Generally Available
Deno released celld in August as an open-source alternative intended to let applications built for Workers run with other providers. Cloudflare says celld was designed for compatibility with its implementation while supporting self-hosting and scaling. That gives the new effort a starting point for addressing the scaling gap Cloudflare acknowledges in workerd.
Cloudflare says its own production system for routing Durable Objects is unsuitable for self-hosters because it serves hundreds of locations and depends on external services maintained by site reliability engineers. The company also acknowledges that it has done too little to develop the surrounding tools and services needed for workerd deployments. It says only a few people have used the runtime in production so far.
Cloudflare links its decision to open-source the Workers runtime to feedback from prospective Workers for Platforms customers, including Shopify, in 2022. Those customers required an open-source runtime before they would build on the platform, according to Cloudflare. The company says workerd uses its production runtime code and that some former customers have used it to move away from Cloudflare.
Dahl created Node.js and later developed Deno, a runtime for JavaScript and TypeScript, alongside Belder and the Deno team. Cloudflare says that team brings experience building tools for developers running a runtime on their own infrastructure. Separately, Cloudflare added support for post-quantum-resistant algorithms to Workers’ Web Crypto capabilities earlier this month, including algorithms for key encapsulation and signatures.
