Fastly Unveils Serverless JavaScript with Zero Cold Starts

Global content delivery network (CDN) provider Fastly (NYSE: FSLY) has announced the availability of JavaScript in its [email protected] offering, allowing developers to build with even more flexibility in Fastly’s serverless compute environment.

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“When we launched [email protected] with a language-agnostic vision, JavaScript wasn’t one of the languages we evaluated for support, because at the time, it couldn’t compile to WebAssembly, meaning we wouldn’t have been satisfied with the security of JavaScript within our serverless compute environment,” said Tyler McMullen, Chief Technology Officer (CTO) at Fastly. “However, since we released [email protected], JavaScript has been the most requested language to add, so it was top of our priority list once WebAssembly supported it.”

“Today, we’re thrilled to open up a serverless, zero-cold start JavaScript offering with a reduced attack surface, compared to similar offerings on the market,” added Mr. McMullen. “With serverless computing on the rise, we hope this motivates continued adoption of a powerful technology for businesses as they build modern digital experiences.”

About Cold Starts

Photo Tyler McMullen, Chief Technology Officer (CTO) at Fastly
“Since we released [email protected], JavaScript has been the most requested language to add, so it was top of our priority list once WebAssembly supported it,” said Tyler McMullen, Chief Technology Officer (CTO) at Fastly.

In serverless settings, JavaScript developers have had to deal with startup latency of 250 milliseconds or more for years, stated Fastly. Cold starts are a type of latency that causes request processing to be delayed, slowing down time-sensitive applications and websites. To compensate for the delays, developers have attempted to cram more functions into a single serverless deployment, according to Fastly. This would result in higher security concerns owing to a bigger attack blast radius.

Serverless JavaScript has fallen subject to attackers due to the lack of adequate sandboxing between instances on some alternative platforms, added Fastly, and developers have had to choose between avoiding serverless technology or accepting the safety and performance flaws.

Fastly would solve for both of these challenges through key architectural decisions made when [email protected] was initially built. Fastly constructed [email protected] utilizing WebAssembly instead than depending on existing technologies for serverless compute, such as reusable containers.

Serverless Platform

Fastly’s clients can now run JavaScript code without worrying about cold start times thanks to [email protected]’s high-performance technology, which would allow it to scale with starting speeds that are extremely fast. Fastly created a unique, highly secured isolation technique that generates and destroys a sandbox for every request from JavaScript generated using WebAssembly with security in mind.

“JavaScript is the most popular programming language today by a distance, continuing to grow and find new niches,” said James Governor, analyst and co-founder of RedMonk. “Serverless platforms are a natural home for new JavaScript workloads. Performance and security remain key concerns, and speed is a killer feature. A reduced attack surface and no cold starts is likely to be attractive to modern web developers.”