Deno joins Cloudflare to improve self-hosted Workers and Durable Objects

The work moves toward self-hosting

The Deno team is joining Cloudflare. In Cloudflare's announcement, Ryan Dahl and Kenton Varda describe an effort to combine the Workers runtime with celld, Deno's work on running the Workers programming model across machines you operate yourself.

Cloudflare plans to merge code and ideas from celld into workerd. For developers assessing hosting options, the announcement identifies a specific engineering direction. It does not establish that the combined implementation is ready for every production workload today.

The gap is distributed state

The practical question is how an application keeps state while its work moves across servers. Durable Objects provide individually addressable instances with local SQLite storage and support for real-time connections. Dahl uses chat channels to explain how developers can divide state and connections between objects.

The announcement identifies a limitation in self-hosted workerd: its existing Durable Objects support operates on a single instance. Cloudflare describes that implementation as suitable for local testing but unable to provide the distributed scaling its hosted platform offers.

The proposal therefore concerns more than a choice of JavaScript runtime. A team interested in running stateful applications elsewhere needs to examine routing, placement and storage behavior together. Franklin's interpretation is that this combination deserves its own deployment experiment, separate from checking whether ordinary application code starts successfully.

What a developer can do now

The announcement says developers can start self-hosting celld or workerd today. It also promises further announcements over the coming months, leaving the combined effort's delivery details open.

For an evaluation, choose a small application that exercises the state you actually need. Record the behavior you expect during a restart or a move between machines, and compare it with what the chosen runtime supports. Existing availability is a starting point for that test; the announcement alone cannot settle operational readiness or the cost of running the system yourself.