---
title: 'How Durable Objects work'
summary: 'celld brings the Durable Objects model to compatible infrastructure beyond Cloudflare. Two short videos explain the model and the runtime beneath it.'
publishedAt: 2026-08-11
updatedAt: 2026-08-13
readingTime: 1 min read
tags: durable-objects, celld, distributed-systems, gpt-5.6, remotion
featured: true
---

Ryan Dahl released [`celld`](https://github.com/denoland/celld). It brings Workers and Durable Objects to compatible infrastructure beyond Cloudflare, making the model useful in custom systems and easier to adopt without fear of vendor lock-in.

A Durable Object starts with a simple boundary: one named entity, its state, and the decisions that change it. The process serving the object can disappear; the object remains.

What does that change when designing a system? Start with this boundary and follow it far enough to see where it helps—and where it should end.

```video
/media/celld/durable-objects-explained.mp4
/media/celld/durable-objects-explained-poster.jpg
Durable Objects, explained
```

## Keeping the promise

The runtime has a harder job: preserve that abstraction across replaceable processes and machines. `celld` is one answer. Follow a Durable Object through a failure and see how it continues elsewhere.

```video
/media/celld/durable-objects-under-the-hood.mp4
/media/celld/durable-objects-under-the-hood-poster.jpg
Durable Objects, under the hood
```

GPT-5.6 made both videos as animated Remotion slide shows under my direction.

[Writing Practice](/posts/a-writing-agent-with-durable-objects) explores the same boundary for agentic work: one Durable Object for each long-lived writing task.