Fastly Brings the Wasmtime Team In-House!

Originally brought to my attention by steved09 here: (I’m starting a new thread to add background, a better subject and in case that thread is killed a lawsuit mention)

Sited article by the Bytecode Alliance (jumps down to this topic here):…


"Lucet is designed to take WebAssembly beyond the browser, and build a platform for faster, safer execution on Fastly’s edge cloud. WebAssembly is already supported by many languages including Rust, TypeScript, C, and C++, and many more have WebAssembly support in development. We want to enable our customers to go beyond Fastly VCL and move even more logic to the edge, and use any language they choose. "

  • Another background article from March, 2020, that talks a bit more about the tech at play here: “How Lucet and Wasmtime make a stronger compiler, together”:…
    "We believe WebAssembly will help define high-performing, secure edge compute. And when we open-sourced Lucet — the first WebAssembly runtime designed for edge computing — we knew it would be useful beyond the edge. This is one reason we formed the Bytecode Alliance, an open-source community focused on improving WebAssembly-based compilers, alongside Mozilla, Intel, and Red Hat.

The other high-performance WebAssembly runtime from the Bytecode Alliance is Wasmtime. It shares many core components with Lucet, and was developed at Mozilla during the period where Lucet was still a closed-source prototype."

The article talks a bit more about how great these initiatives fit together, each bringing some important stuff to the table (which is why they already were working together).

Back to the article that triggered this thread…

"The Lucet and Wasmtime teams join forces
Merging Lucet and Wasmtime has been the plan since we announced the BA. And it’s about to get a lot easier to execute on that plan, since the Wasmtime team is moving to Fastly! :tada:

What does this mean for Bytecode Alliance projects?

Mozilla will continue to have a team working on WebAssembly in Firefox, focused exclusively on the needs of web developers. As part of this, they will continue working on the Cranelift code generator, used by many projects including Firefox, Lucet, and Wasmtime.

Fastly will take on sponsorship for the work on the outside-the-browser projects that were hatched at Mozilla, including Wasmtime and WASI, and we look forward to expanding the scope of that work further.

This is a testament to the collaborative, multi-stakeholder setup of the Bytecode Alliance. It doesn’t matter where we work—we’re still working together."

This is amazing! I have sort of a medium depth understanding of the details. At the risk of getting some wrong…

This is about one of the lowest layers of Fastly’s “programmable network”. It is like the operating system all the applications will run on top of. Technically the goal is to have this sit on top of ALL operating systems making any code written work in the browser, your phone, computer or in Fastly Instances. Maybe think of this like a multi-country travel power adaptor you might carry with you on a big trip through Asia and Europe, but instead of the wall socket you have Windows, MacOS, iOS, Andriod, your browser, etc, and the device is this layer that Fastly is now building in-house (except for the web-developer-oriented side that stays at the Mozilla Foundation).

So a developer will write some application in whatever language they want and then use Fastly’s compiler tools to spit out a packaged up version of the app that will run on this platform. Fastly also makes a runtime environment to host the app on their network so when the app is running they can take full control and provide, I think, things like security, hardware resource management, startup speeds, etc.

I still don’t know what the time-line and business impact will be so it is hard to say how investable this is. It WILL give them an advantage but we don’t know how significant or when. I expect a large part of this to be open-sourced, but the advantage of having the tools and runtime to use the results of developer adoption in an accessible and frictionless way is where they maintain value after driving and sharing this next generation technology. Open-sourcing is all about giving away the platform for max adoption and outside collaboration to build a robust result. Once everyone agrees it is the best way to develop applications it is pretty awesome when your company offers the best way to run them (and earns revenue on the usage).

Again, I’m not sure how investible this is/will be. Maybe we’ll know more next year. For now this isn’t part of my investment thesis per se, but it all goes to show how strong Fastly’s culture of innovation is and THAT IS relevant for their current business wins and retention. Some customers, like Shopify, are using this stuff today, or at least developing on it and helping Fastly push it forward. I don’t think this will be a black & white product reveal. Adopters will ease in at first and eventually accelerate.