Software Engineer at Bloomberg. Opinions are my own.
Joined June 2009
- Tweets 282
- Following 1,310
- Followers 212
- Likes 9,204
24 Photos and videos
Thomas Chetwin retweeted
Our engineers @bloomberg have been contributing to the #JavaScript ecosystem for more than a decade. So, it's time they had somewhere to tell their story.
This week, we are setting up our new #JS engineering blog. More posts will follow soon!
bloom.bg/3OQsgYd
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Thomas Chetwin retweeted
26 Oct 2025
JavaScript top-level await is no longer considered 'baseline' due to a pretty big Safari bug caniuse.com/mdn-javascript_o…
The module graph fails in cases where two modules import a third at the same time. Demo: random-stuff.jakearchibald.c…
It's best to avoid the feature for now 😔
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Thomas Chetwin retweeted
4 Jul 2025
Ecma Recognition 😉
This award for my work as co-chair of @TC39 for the last five years was a lovely surprise 🙏
I'm grateful for the sustained encouragement & support from leadership at @TechAtBloomberg championing the value of open source & standards 👍
3 Jul 2025
The 129th General Assembly held in Geneva on 25 June 2025 approved four new Ecma recognition awards to honour Touradj Ebrahimi, Hyun Kahng, Robert Palmer and Michael Saboff for their contributions and services to Ecma. More information is available at ecma-international.org/news/
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Thomas Chetwin retweeted
8 May 2025
Here's why the Records and Tuples proposal died, and how Composites might solve it.
I did my homework for this one - I interviewed @acutmore, the Composites TC39 champion. And I'm really proud of how it turned out.
I'd love any feedback you can give me, and I'll make any necessary adjustments before it goes live.
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Thomas Chetwin retweeted
9 Nov 2024
✨ dtsx is a fast new DTS emitter for TypeScript.
It leverages tsconfig "isolatedDeclarations" to ensure that source code is sufficiently annotated with types.
We have been working hard these past few weeks on creating a very fast .d.ts emitter, using @bunjavascript.
And we finally have a release out that works across our packages.
📢 Say welcome to... dtsx!
ALT Screenshot of the dtsx readme
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Thomas Chetwin retweeted
30 Oct 2024
📷Huge thanks to @TechAtBloomberg for being a #gold sponsor at @NodeConfEU 2024!! Your partnership is helping us create something truly special. 📷 #Sponsorship #Techatbloomberg #gold #waterford #ireland #techevents
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🚀 Node.js 23 is here! 🚀
New features, performance boosts, and a smoother developer experience. With better compatibility and stability, Node.js 23 delivers more power for building efficient apps.
Read here: 👉hubs.la/Q02TFFXp0
#NodeJS #JavaScript #WebDevelopment
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Thomas Chetwin retweeted
9 Oct 2024
TypeScript 5.7 beta is now available to try! Read up on what's new today! devblogs.microsoft.com/types…
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Thomas Chetwin retweeted
1 Oct 2024
TypeScript London is tomorrow 😮
After two new open source releases, here's the line up:
🔷 @alistaiir to kick us off
🔤 Stricli: Building Better CLIs
🪿 Porffor: Type-Driven Runtime Optimizations
👻 ts-blank-space: Faster TypeScript Compilation
And some very special guests 💙
18 Sep 2024
We're hosting our first London #TypeScript Community Meetup at @Bloomberg's EMEA HQ in London on Wed., October 2 (18:00 BST).
Join us for 3 exciting talks & to meet London @typescript community members, including some TypeScript contributors.
bloom.bg/4enU9OF
#opensource
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Thomas Chetwin retweeted
1 Oct 2024
I'm excited to announce Stricli, a brand new #opensource framework for building type-safe, lazy-loaded CLI applications with #TypeScript.
We developed this framework for our internal CLIs at @TechAtBloomberg, and now we want to share it with the world.
bloomberg.github.io/stricli/…
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Thomas Chetwin retweeted
28 Sep 2024
Now w/ 20 years SpiderMonkey experience, ~15 v8/Node, Chromium etc. we’ve assembled one of the best sets of passionate JS ecosystem engineers in NYC/London.
London! Go meet Rob (TC39 co-chair) and everyone doing amazing things with JS/TS in London HQ on Wednesday!
18 Sep 2024
We're hosting our first London #TypeScript Community Meetup at @Bloomberg's EMEA HQ in London on Wed., October 2 (18:00 BST).
Join us for 3 exciting talks & to meet London @typescript community members, including some TypeScript contributors.
bloom.bg/4enU9OF
#opensource
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Thomas Chetwin retweeted
26 Sep 2024
TypeScript 5.7 will load 2.5x faster than TypeScript 5.6 when run in Node 22 , thanks to @JoyeeCheung's work to provide an offical API for V8 compile caching.
That's 60% less time waiting for tsc/tsserver to actually start doing work.
PR: github.com/microsoft/TypeScr…
ALT hyperfine/poop benchmarks of "tsc.js --version" with and without V8 module caching; hyperfine showing 2.53x faster, poop showing 60% less wall time, and every other metric better as well
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Thomas Chetwin retweeted
19 Sep 2024
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…
ALT the ts-blank-space logo. the "ts-" has a blue background and "blank-space" has an orange background.
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Thomas Chetwin retweeted
18 Sep 2024
We're hosting our first London #TypeScript Community Meetup at @Bloomberg's EMEA HQ in London on Wed., October 2 (18:00 BST).
Join us for 3 exciting talks & to meet London @typescript community members, including some TypeScript contributors.
bloom.bg/4enU9OF
#opensource
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Thomas Chetwin retweeted
17 Sep 2024
(1/2) @Bloomberg is excited to join the Unicode Consortium (@unicode) as a Supporting member, where we'll have the opportunity to help advance the state of internationalized software for global financial applications
bloom.bg/3Twl1UI
#opensource
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Thomas Chetwin retweeted
23 Aug 2024
The release candidate for TypeScript 5.6 is now available for testing! Give it a try today for more new checks, ways to speed-up your builds, new JS features, and more!
devblogs.microsoft.com/types…
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Thomas Chetwin retweeted
22 Aug 2024
Node.js 22.7.0 is out 💚
* Experimental Node.js to support TypeScript syntax such as Enum and namespace🙌
* Module syntax detection is now enabled by default 🙌
* Faster Buffer.copy & Buffer.write ⚡
Check it out nodejs.org/en/blog/release/v…
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Thomas Chetwin retweeted
21 Aug 2024
Node.js v20.17.0 (LTS) is out 🎉
Some notable changes include:
- module: support require()ing synchronous ESM graphs
- path: add matchesGlob method
- stream: expose DuplexPair API
Link to the full release notes 👇
nodejs.org/en/blog/release/v…
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Thomas Chetwin retweeted
19 Aug 2024
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…
ALT Promotional banner: Thank you to our sponsor Bloomberg Engineering. SquiggleConf, October 3-4 2024. Boston New England Aquarium
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Thomas Chetwin retweeted
19 Aug 2024
We’ve published lots of videos on Chrome Extensions lately! New today, here’s an explainer I worked on about content scripts: youtu.be/ezhJezGX5ak
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