Jason Williams (@Jason_williams) header
Jason Williams (@Jason_williams) profile picture

JavaScript Infrastructure & Tooling @Bloomberg, creator of @boa_engine

London
Joined May 2008
Photo by Jason Williams (@Jason_williams)Photo by Jason Williams (@Jason_williams)Photo by Jason Williams (@Jason_williams)Photo by Jason Williams (@Jason_williams)Photo by Jason Williams (@Jason_williams)Photo by Jason Williams (@Jason_williams)Photo by Jason Williams (@Jason_williams)Photo by Jason Williams (@Jason_williams)Photo by Jason Williams (@Jason_williams)Photo by Jason Williams (@Jason_williams)
⚙️ Building a JavaScript Engine in Rust: Lessons From Boa A deep dive by @Jason_williams into building Boa, a JS engine in Rust, and what it takes to parse and execute JavaScript under the hood. From experimentation to influencing V8 itself, this is the story of how an open-source project can shape the broader JS ecosystem. 🔗 Full recording: gitnation.com/contents/build…
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In his #JSNation 2026 talk (10:25 AM EDT) today, senior software engineer @jason_williams shares his journey creating #Boa, a #JavaScript engine written in Rust, and what it taught him about how #JS works under the hood bloom.bg/3Qp5DuX
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Temporal is now Stage 4 at TC39 🎂🎂🎂 Thanks to all the other champions of JavaScript's new date-time API. It has been a wild ride over many years! I wrote a blog post explaining how we got here 📜 🧵
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Meet @Jason_williams, Senior Software Engineer at @Bloomberg L.P., making the web faster⚡️ From V8 optimizations to Container Timing, he’s shaping JS performance. Creator of Boa (Rust JS engine) & ECMAScript contributor. Catch his talk at JSNation: jsnation.com/
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Jason Williams retweeted
ECMAScript excitement 😉 Congrats to @ManishEarth on unflagging @TC39 Stage 3 Temporal in V8 today. Heading for Chrome 144 🎉 By many metrics this new date/time API is the single biggest change to JS ever 🔥 It uses Boa's temporal_rs by @Jason_williams Kevin Ness & Manish 👍
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temporal_rs has been released!!! This is the first public release of temporal_rs, a Rust implementation of the Temporal API powering Boa, Kiesel, V8 plus other engines. This will be shipping in Chromium soon More info in our blog post: boajs.dev/blog/2025/09/24/te…
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Jason Williams retweeted
The Bloomberg Terminal, believe it or not, is based on web technology 🌐 This deep-dive talk by @Jason_williams & @pcwilliams reveals what that looks like in terms of Chromium embedding. And has led to creating a new Web Perf API: Container Timing 🔥 youtube.com/watch?v=y1MCLZm8…
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Jason Williams retweeted
The @PerfNowConf conference begins tomorrow in Amsterdam. It is going to be great 👍 For the first time @pcwilliams & @Jason_williams will share the story of how the Bloomberg Terminal uses web tech & what this means for the wider web ecosystem 🎉 If you see us, come say hi 👋
Are you ready for #PerfNow this week? Who's joining us remotely?
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It’s been interesting following the work on this over the years, great to see it paying finally paying off. I hope we see a deeper dive on those perf improvements and changes @BenjaminPasero
📦 a 2y journey to adopt ECMAScript modules in @code is coming to a successful end 🚀 we see massive startup performance improvements loading our main VS Code module Thanks Jo and @alexdima123 from the team for this joint effort 🙏 👉 code.visualstudio.com/inside…
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Jason Williams retweeted
TypeScript excitement 😉 Congrats to @acutmore on releasing a brand new type-stripping compiler: ts-blank-space ✨ ⚡️ 5.6x faster than tsc due to zero-codegen 🔷 Written in TS 💯 Uses the official TS parser 🎯 Accurate/preserved source locations 💪 Battle-tested in production
Today, I'm releasing a TypeScript compiler called ts-blank-space 🎈 We use this at @TechAtBloomberg to perform type-stripping on a modern subset of TypeScript. It's written in TypeScript and is fast because it uses whitespace to enable work-skipping. bloomberg.github.io/ts-blank…
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We just added some more speakers to our #PerfNow line-up for November 14 and 15. @ericwbailey, Paul Williams, @tameverts, @ksylor, @Jason_williams and @Jack_Franklin will be with us as well! perfnow.nl
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Jason Williams retweeted
We're proud to announce @TechAtBloomberg as a sponsor of SquiggleConf 2024! ✨ Bloomberg runs one of the world's largest information networks, powered largely by web tech. Its engineers have contributed to many of the latest & greatest web dev tools, including TypeScript's Isolated Declarations feature & private class fields support. TechAtBloomberg.com/javascri…
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Jason Williams retweeted
We got an email from the Serbian Registry of Internet Domain Names (RNIDS), the organisation that is responsible for the `.rs` top-level domain. Looks like they are a big fan of Rust. 😊
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Boa 0.18 has just been released! Boa is a #javascript engine written in #rustlang. It now passes 85% of the official ECMAScript suite, and it's much more performant! Check the full release post here: boajs.dev/blog/2024/03/07/bo… /cc @rustlang @ThisWeekInRust
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Jason Williams retweeted
The web changed today. Alternative browser engines on iOS developer.apple.com/support/…
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This is unexpected. @deno_land we didn't know of any implementations in JS engines that pass all the compliance tests yet. will it be behind a flag? – at Islington, London
temporal coming soon to Deno 1.40
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Jason Williams retweeted
.@TechAtBloomberg engineers out and about at @PerfNowConf in #Amsterdam. Thanks #PerfNow for a great conference. We will be back! – at Amsterdam, The Netherlands
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