Serverless Compute Environment

Compute@Edge is the next generation of serverless computing. It combines the best in emerging technology to give developers unmatched power, scalability, security, and speed at the edge.


We built Compute@Edge on WebAssembly, a technology we’ve been collaborating on with the Bytecode Alliance. WebAssembly is uniquely suited to empower developers to write code in their preferred language, then run that code anywhere at near-native speeds.


Lucet, our native WebAssembly compiler and runtime engine, helped us build a platform for fast, safe code execution on Fastly’s edge cloud. We originally looked at existing WebAssembly/multi-tenant runtimes like Google's V8, but its performance and security models led us to build our own. 

Lucet can instantiate WebAssembly modules in under 50 microseconds with just a few kilobytes of memory overhead. By comparison, Chromium’s V8 engine takes about 5 milliseconds, and tens of megabytes of memory overhead, to instantiate JavaScript or WebAssembly programs. By combining WebAssembly and Lucet we believe we offer a faster and more secure experience for our customers than anything available off-the-shelf today.

Isolated Sandboxing

Compute@Edge creates and destroys a sandbox for each request as it flows through our platform. Operating within microseconds, this cutting-edge technology reduces the attack surface and eliminates side-channel attacks. It also lets us limit the blast radius of buggy code or configuration mistakes from other users and reduces resource contention.


Since day one we’ve been building on the edge with our customizable Varnish Configuration Language that allows for intelligent caching, moving application logic to the network edge, and tailoring experiences based on end user location, language, and device type. 

Compute@Edge frees developers from typical serverless computing constraints by enabling the use of any WebAssembly-supported language. WebAssembly is an intermediate format that is currently compatible with multiple programming languages such as Rust, AssemblyScript, Java, C/C++, .NET, and Go. Compute@Edge supports two languages today, Rust and AssemblyScript (beta), with more to come in the future.

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We’re pushing edge innovation even further with Fastly Labs. Your developers can explore our latest projects, and interact with experimental, in-progress ideas — all giving your teams an edge, and empowering them to step into the future, faster.

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Build on a developer-trusted platform.

We built Compute@Edge on a powerful foundation so that you can take advantage of all of the benefits of going serverless at the edge. We’ve taken this one step further with ready-to-deploy recipes that help you execute your serverless code on one API-powered platform. Get hands-on with our technology today at our Developer Hub — where you’ll find our developer tools, world-class documentation, and critical assets to help you get started.

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