The Vercel of Flutter

Celest is a backend-as-a-service for Flutter and Dart developers. It empowers Flutter developers with the tools and capabilities they need to become full-stack developers. We are introducing "Cloud Widgets", a set of primitives which enable you to declaratively define every piece of your backend and infrastructure in Dart. As the role of the front-end developer evolves towards full-stack proficiency, we recognize that existing tools have fallen short for those specializing in Flutter. Using the programming language and patterns Flutter developers already know from building their frontend, Celest enables developers to build and connect their apps to their backend with no additional tooling. We enable Flutter developers to concentrate on building features and delivering value to their customers rather than learning additional domains and fragmenting themselves across disparate toolchains.

Team Size:1
Location:San Francisco
Group Partner:Dalton Caldwell

Active Founders

Dillon Nys

Founder & CEO at Celest. Previously, I wrote the Amplify Flutter framework at AWS.

Dillon Nys
Dillon Nys

Company Launches

When I was at AWS building Amplify Flutter, I found myself wanting to write more and more of my code in Dart. I loved being able to maintain my flow state and use a single programming language—one I’d grown quite fond of—for everything. CLIs, tooling scripts, HTTP servers… if I needed a piece of code, I would find a way to write it in Dart.

The ecosystem for these use cases was immature but that just made it a challenge, which I loved. Use the right tool for the job, you may say. Nah… I want to use Dart. I thought I was alone in this quest but, I was okay being the crazy one.

And then, to my surprise, our customers began asking

“When can I write my Lambdas in Dart?”

“When is AWS going to release an SDK for Dart so I can use it in my backends?”

It dawned on me that there was perhaps something deeper we were all experiencing, something more fundamental about coding being expressed.

JavaScript is one of the most popular server-side languages in use today. A reasonable person with no knowledge of JavaScript may conclude from this that it’s because JavaScript is performant, efficient, or otherwise designed for the server.

The reality, though, is that developers will often seek the path of least resistance in an environment replete with friction. It’s easy to deride a choice in language, but it’s hard to downplay the numbers. Software engineers are human, after all—and humans are constantly optimizing their flows.

Flutter was born from a desire to solve this age-old quest of optimization—first, as a way to build iOS and Android apps from the same codebase, saving teams the burden of managing two separate products. Then, to desktop and web applications, dramatically reducing the barrier to entry for these platforms too. The vision is largely realized. And, thanks to Dart, it’s been done without sacrificing performance.

Our mission with Celest is to fill in the last piece of this puzzle—the cloud. We do that, simply, by starting and ending with Dart.

Here’s how you define a cloud function with Celest.

And here’s how you add authentication.

To test it out, you run celest start and iterate on your backend locally as you build your Flutter app. Your functions hot reload as you save your changes, and integration comes free with an auto-generated client library.

And when you’re ready to turn this into a fully managed and auto-scaled backend, you run celest deploy. That’s it.

As a Flutter developer, I’ve never left the Dart programming language, never thought about the many layers of abstraction beneath, and didn’t even need to leave my IDE to solve an otherwise laborious and flow-breaking task. I’m back to writing my app in less than 5 minutes. It feels like I’d never left.

Celest is the product I always wanted as a Flutter developer, the tool I had felt crazy for wanting at one point. It feels a little less crazy now, but only time will tell :-)

You can try and play with Celest for free today. Our cloud offering has started rolling out to the waitlist and will be publicly available in the coming weeks. For this and all the other goods in store, check us out @ celest.dev

And if this story rings true for you (or not), I’d love to hear your thoughts


To the crazy ones 😎 🎯

Dillon, Chief Celestial

Company Photo

Company Photo

Hear from the founders

How did your company get started? (i.e., How did the founders meet? How did you come up with the idea? How did you decide to be a founder?)

Dillon has been a member of the Flutter community since 2018 and worked at AWS on the Amplify Flutter product for two and a half years. At AWS, he created the first comprehensive Dart SDK, aimed at helping Flutter developers connect their apps to AWS. This SDK received positive reception within the Flutter community. However, he identified a persistent challenge: Flutter developers were still facing difficulties in crafting their backends, since it required them to spread themselves across different toolchains and programming languages. Recognizing this gap, Dillon left AWS with the idea of creating a dedicated platform for Flutter developers to unlock their ability to build every part of their apps in Dart. He submitted an application to Y Combinator only an hour before the deadline and was accepted into the Winter 2024 batch. Now, he’s able to realize the vision started at AWS: significantly improving the Flutter development landscape.

What is your long-term vision? If you truly succeed, what will be different about the world?

Our vision is centered on expanding the capabilities and reach of Flutter and Dart developers. By providing a solution that facilitates backend development in Dart, we are enhancing and completing the story for the Flutter and Dart ecosystem by making Dart a comprehensive language for building full-stack applications. Dart's strong typing and sound design patterns make it an attractive alternative for those currently using JavaScript/TypeScript for web development. Ultimately, we aspire to make Flutter and Celest synonymous with app development in general, revolutionizing the way apps are built regardless of the platform or device types being targeted.

Selected answers from Celest's original YC application for the W24 Batch

What is your company going to make? Please describe your product and what it does or will do.

We're crafting an event-driven, extensible platform tailored to Flutter[1] developers, enabling them to build cloud-connected apps using the programming language and tooling most familiar to them. In today's world, the front-end developer role is rapidly expanding towards full-stack proficiency. But full-stack has failed Flutter developers, and their tooling is at fault.

Flutter developers are demanding more integrated and holistic tooling so they can focus on what matters most--solving their users' problems. While platforms like Vercel[2] empower web developers with a fully-managed cloud offering, Flutter lacks a counterpart. Our platform fills this gap, providing a swift and intuitive experience for this under-served and growing market.

From the first line of code to the final cloud function, we aim to be the Vercel of Flutter's renaissance.

[1]: A cross-platform UI development framework by Google (https://flutter.dev/) [2]: A managed web development platform (https://vercel.com/)