Jon Gjengset

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

[Jon Gjengset @jonhoo]

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.

[Anish Athalye @anishathalye]

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!

[Jon Gjengset @jonhoo]

@GergelyOrosz I've played around with calling it "power coding". In many ways it feels similar to powertools in construction — speeds up work, not appropriate for all tasks, and dangerous if used carelessly.

[Jon Gjengset @jonhoo]

@simonw But I will add that liberal use of YouTube chapters in the video is pretty helpful, because it means that _if_ you spend half an hour digging yourself out of a (fascinating) hole, those with less time to spare can skip over it easily.

[Jon Gjengset @jonhoo]

@simonw As someone who does the live coding approach exclusively, I've gotten repeated feedback that people really enjoy watching me get stuck and then learning from the process I use to get un-stuck. That's the stuff that tends to get lost in the "here's one I made earlier" version.

[Jon Gjengset @jonhoo]

@NotNordgaren @theodorvaryag @LundukeJournal @nostarch Or https://t.co/PJqI0coiTd !

[JetBrains @jetbrains]

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 👉 https://t.co/7G7kk3J20m

#AI #JetBrains #SoftwareEngineering #RustRover #RustLang #Programming

[Jon Gjengset @jonhoo]

@hochej @mitsuhiko I don't think I'm skeptical enough for what Armin is looking for here. Though would always be happy to chat to him :p Have spent the past week since my stream immersing myself in using Claude Code, and definitely have a deeper (but not all that *changed*) perception now.

[Anish Athalye @anishathalye]

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.

[James Cowling @jamesacowling]

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.

[Jon Gjengset @jonhoo]

As for where "elsewhere" is, they're all listed on https://t.co/Zgw3jYsHeL, and at the time of writing includes YouTube, Discord, LinkedIn, Bluesky, and Mastodon. See you all there!

[Jon Gjengset @jonhoo]

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.

[Jon Gjengset @jonhoo]

New year, new Q&A; 1/1 at 5:30pm UTC: https://t.co/CdLFhQfmyq.

Bring out your questions, however deep or superficial, and I'll do my best to answer 😅 Vote on questions and propose your own at https://t.co/1Qe8Iw3CUo starting now!

Stream will be at https://t.co/KYvQNkWITM 🍿🙋

[Jon Gjengset @jonhoo]

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!): https://t.co/3fykiBlkAQ

[Jon Gjengset @jonhoo]

@burntsushi5 In my case someone apparently "gifted" (or so a random notification that then disappeared said). Maybe the same happened to you?

[Smarter Every Day @smartereveryday]

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

[EuroRust @euro_rust]

🎥 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 📺 https://t.co/aNppQ7UwSE
Go and check out his other works!

Watch Jon's video here ➡️ https://t.co/hwm5LtM9U0

#rustlang #techeducation #crustofrust

[EuroRust @euro_rust]

🎉 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

🔗 https://t.co/oUgKxR2vl2

#rustlang

[Jon Gjengset @jonhoo]

Recording of today's stream where we decrusted the quickcheck property testing crate is now up!
https://t.co/oaYdVnyagi

[Jon Gjengset @jonhoo]

Time in your timezone:

[Jon Gjengset @jonhoo]

Short notice, but tomorrow @ 8am UTC (https://t.co/DSee6MyMtK) 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 https://t.co/IYhI3bqNdd 🦀