Rust live-coder and OSS tinkerer who loves teaching. I try to keep a high SNR. Wrote Rust for Rustaceans. At @HelsingAI. Ex AWS. Co-founded @readysetio. he/him
Oslo, Norway
- Tweets 6,585
- Following 189
- Followers 36,201
- Likes 16,929
Pinned Tweet
As the year is about to close, it's about time to say good-bye to Twitter. I'm not deleting the account or old tweets, I'll still monitor for mentions and DMs, and if something has _only_ been posted to Twitter I may retweet here. But all announcements will go elsewhere.
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Jon Gjengset retweeted
In January, @jonhoo, @jjgort, and I returned to @MIT_CSAIL to teach Missing Semester, a class on topics missing from most CS programs—tools and techniques that everyone should know, like Bash, Git, CI/CD, and AI tools. Today, we’re releasing the course for free online!
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Jon Gjengset retweeted
Should developers quit because of AI? 🤖
@VBragilevsky talked with @jonhoo about AI, programming, salaries, job market specifics, and of course, Rust 🦀
Watch the full interview for more insights 👉 jb.gg/JGrr25Xjb
#AI #JetBrains #SoftwareEngineering #RustRover #RustLang #Programming
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Jon Gjengset retweeted
Missing Semester has grown past 100K subscribers on YouTube. Appreciate all the engagement and support!
We plan to teach another iteration of the course in January 2026, revising the curriculum and covering new topics like AI IDEs and vibe coding.
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Jon Gjengset retweeted
How to be a Principal Engineer/Senior Principal Engineer/Senior Architect/fancy-sounding-title Engineer, a thread:
1. You're evaluated on how much more the company succeeds because you're there, not the lines of code you wrote. If you can unblock someone, do that. If you need to kill a two year project that's not going anywhere, do that. Do what is right, not what makes you look good.
Very interesting. Do you have more insights into senior principal engineer role for somebody who considers it as a next milestone on their carrier path?
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As the year is about to close, it's about time to say good-bye to Twitter. I'm not deleting the account or old tweets, I'll still monitor for mentions and DMs, and if something has _only_ been posted to Twitter I may retweet here. But all announcements will go elsewhere.
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As for where "elsewhere" is, they're all listed on jonhoo.eu, and at the time of writing includes YouTube, Discord, LinkedIn, Bluesky, and Mastodon. See you all there!
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New year, new Q&A; 1/1 at 5:30pm UTC: everytimezone.com/s/03a3a76f.
Bring out your questions, however deep or superficial, and I'll do my best to answer 😅 Vote on questions and propose your own at wewerewondering.com/event/01… starting now!
Stream will be at piped.video/live/eMuGHXMjJTU 🍿🙋
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Perhaps unsurprisingly, I have a bunch of Opinions™ on work-life balance and time management. Lately, I've been particularly bugged by the common belief that employer incentives don't align with employee well-being. So, I wrote a thing (with graphs!): thesquareplanet.com/blog/abo…
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Jon Gjengset retweeted
Hey it's me Destin, from Smarter Every Day. Now that it's time to elect America's next leader, I would like to share something very interesting and important with you. I've been paying attention to this for a while, and I think if you look for it, you see it too.
🧵 1/n
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Jon Gjengset retweeted
🎥 The first #eurorust24 video is here! Starting off strong with @jonhoo , the Principal Engineer at @HelsingAI , as he teaches fundamental concepts of Rust that can be challenging for newcomers. It’s a masterclass in effective Rust education!
Btw, Jon 🦀 is also the author of Rust for Rustaceans and the creator of the Crust of Rust YouTube series 📺 buff.ly/4f44nED
Go and check out his other works!
Watch Jon's video here ➡️ buff.ly/3NO9DAf
#rustlang #techeducation #crustofrust
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Jon Gjengset retweeted
🎉 New and FREE at #eurorust24: Competitive Control Systems Hackathon by Helsing! Build a control system in Rust for a virtual quadcopter, compete live on a leaderboard, and test your creativity. Limited seats—grab yours now!
Mentors: Dr. Robert Fink, @jonhoo , Cécile Allano , Omar Essaid
🔗 eurorust.eu/workshops/hackat…
#rustlang
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Recording of today's stream where we decrusted the quickcheck property testing crate is now up!
piped.video/64t-gPC33cc
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Short notice, but tomorrow @ 8am UTC (everytimezone.com/s/f47dc299) I'll decrust the quickcheck crate! We will explore what property testing is, how quickcheck lets you do it, how to go "more advanced", and how it all works under the hood.
Come join at piped.video/live/53JgWT9Ugg8 🦀
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The recording of the stream where we implemented a lexer and parser for the Lox language from Crafting Interpreters in Rust is now up, and I think it turned out really good! Clocked in at 8h, but it's split into chapters to not be so daunting to follow :)
piped.video/mNOLaw-_Buc
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Follow along or come up with your own solution first and then compare, whichever you prefer — you can access the challenge for free through app.codecrafters.io/join?via…, or in free source form (without the nice infrastructure) at github.com/codecrafters-io/b….
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I've been looking to stream writing an interpreter for a while, and @codecraftersio have just released a challenge in beta following @munificentbob's Crafting Interpreters book! So, this Saturday @ 1pm UTC (everytimezone.com/s/416927f0) we'll give it a try 🧑💻
piped.video/live/FdZmJ0DAmn4…
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Come join me live, or try it yourself and compare notes with the VOD after the fact! You can access the challenge over at app.codecrafters.io/join?via…, or in free source form at github.com/codecrafters-io/b….
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The Crafting Interpreters book is craftinginterpreters.com/.
I was particularly inspired to do a stream like this after reading matklad's excellent article on Pratt parsing: matklad.github.io/2020/04/13…
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I often hear claims that (peer) reviews as time-consuming to write and useless to read. Which makes me sad, because they can be invaluable to both the recipient and the org. if written well. So, I wrote a rant about how to write them better:
thesquareplanet.com/blog/wri…
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