Recording of yesterday's stream implementing a WAV noise file generator in #rust is now up on YouTube! We managed to get white, pink, brownian, blue, violet, and grey (psychoacoustic!) noise all implemented, so I'll count that as a success π
youtu.be/zOTE4BN59u4
Posts by Jon Gjengset
A few weeks ago I was interviewed by Daniel from Rock the JVM, a channel (unsurprisingly) for folks in the JVM ecosystem. It was fun to chat about Rust with someone "from the outside", and if you want to hear it, it's now up on his YouTube channel!
youtu.be/Cg8gASzqqOs?...
The past few streams have been pretty high level, but not this time! Friday at 4p UTC (everytimezone.com?t=69cf0300,3c0), we're going back down to "what bits go where". We'll try to write an audio generator that produces WAV files with white/pink/brown noise by hand π
youtube.com/live/BKHE7st...
Back in January I gave a talk at Jane Street titled "Are Mutexes Slow?" (I gave a lightning version of it at @rustikon.dev last week!). And it's now up on YouTube if you're interested in wonky details about CPU cache coherence and the cost of coordination!
www.youtube.com/watch?v=tND-...
Sadly I can't make it to the inaugural TokioConf (Portland, Apr 20-22), but I do have a 15% off code I've been told to hand out to people excited to go! So, if you've been on the fence, ping me and I'll see what I can do! More on the conf & who it's for (most people!) here: tokio.rs/blog/2026-03...
The Missing Semester of your CS education [MIT IAP 2026] - https://missing.csail.mit.edu
In January, @anishathalye.bsky.social, @josejg.bsky.social, and I returned to @csail.mit.edu to teach Missing Semester, a class on topics we miss from most CS programsβtools and techniques that everyone should know, like Bash, Git, CI, and AI tools. Today, weβre releasing the course for free online!
Not *too* much actual ANTLR stuff in there unfortunately, but at least I got to shout out your work in a small way :D Issues now filed:
- github.com/antlr4rust/a...
- github.com/antlr4rust/a...
- github.com/antlr4rust/a...
They _are_ automated, so can't guarantee they're all useful, but from a glance and without knowing the internals of the ANTLR4 Rust code, they _seem_ legitimate.
And third, I've had the LLM do some benchmarking of avdl, and it's come up with some hotspots in the ANTLR4 Rust code based on the resulting flamegraphs β would you be interested in its reports, or not so much?
@alex.wcgw.dev Hey Alex! First, thanks a lot for taking on ownership of ANTLR4 for Rust! Second, I see you made some improvements to the README over the past couple of days β was that because of my stream by any chance? π
Recording of our "port avro-tools' Java-based idl-to-json tool to Rust using an LLM" adventure is now on YouTube! We got to an initial working implementation in ~4hrs (though still bugs to iron out in future iterations), which isn't too shabby! Code at github.com/jonhoo/avdl.
youtu.be/vmKvw73V394
As for the LLM bit β I think this is an ideal powercoding (LLM + code review) use-case since we a) have access to the existing Java code and b) there's an infinite supply of trusted tests (the same IDL passed to the Java tool should produce the same JSON). But let's see how it goes!
If you don't know Avro, it's Apache's equivalent to Google's Protocol Buffers. See avro.apache.org/docs/1.12.0/....
Friday 9a UTC (everytimezone.com/s/5903cd46) sounds like a good time for a stream! This time, we'll try to port Avro's IDL-to-JSON tool from Java to Rust (with LLM help), leveraging the fact that their grammar is written using ANTLR to make our job easier. Come join me π
youtube.com/live/NqV_KhD...
The recording of the new year's Q&A stream is now up, with all the questions annotated for easy skipping! youtu.be/S_zp82fYrGw
Quick reminder that this is coming up. Lots of good questions have come in, so please take some time to go in and vote for the ones you care the most about!
We're nearing the new year, so time for another Jan 1st Q&A! Ask questions at wewerewondering.com/event/01KDDA... β none too big or small. I'll get to as many as I can, and upload the recording after the fact. Stream starts 1/1/26 at 2:30p UTC @ youtube.com/live/g1ZgInF.... Hope to see you there β€οΈ
YouTube silver creator award presented to Jon Gjengset for passing 100,000 subscribers. J and Ferris plushies in the background.
Okay, this is pretty cool.
Video of the One Billion Row Challenge stream is now up at youtu.be/tCY7p6dVAGE! We got down to 1.2s without any external dependencies, and it was a fun journey down lots of performance rabbit holes (only some of which panned out π ). It is over 10h, but hopefully the chapters in the video help!
Oh, forgot the link to see the time in your timezone. YouTube should show it, but otherwise, you can use everytimezone.com/s/70bf2c9d π [4/3]
There are already several Rust implementations (github.com/gunnarmorlin...), this excellent write-up (curiouscoding.nl/posts/1brc/), and even an existing stream (www.youtube.com/watch?v=Q-0d...), but I'm hoping that walking through the process live will still be a good teaching exercise. [3/3]
Come join me on Saturday at 11am UTC over on youtube.com/live/g2EKNXK..., and we'll see what we can squeeze out of it ποΈ [2/3]
I'm late to the party, but the One Billion Row Challenge (github.com/gunnarmorlin...) feels like an excellent way to dig into optimizing Rust code and learning somethings about assembly, SIMD, performance profiling, and just CPUs in general in the process, so let's take it on live! [1/3]
@adamconover.net is here though, and also worth checking out β not as focused on tech and policy, more on fact-finding journalism on everyday topics with a humouristic bent (e.g., "Adam ruins everything").
I don't think Cory is on Bluesky, but his website is pluralistic.net. Highly recommend giving his writings a read (though be warned β he writes a *lot*).
I've been a fan of Cory Doctorow for ages, and this episode of Adam Conover's podcast is a great synthesis of his observations on the tech industry across the board, both what's broken and how we fix it. And a slew of other great insights. Highly recommended listen!
headgum.com/factually-wi...
On Sunday at 2pm UTC (everytimezone.com?t=68fd6480,348), Ben and I are doing another "What's New in Rust" marathon stream for Rustacean Station! I'm guessing ~5h for part 1 π It'll be over at youtube.com/live/6mwVWmK.... Come join us πΊπ
In August, I was interviewed by JetBrains about programming and Rust, ranging from the borrow checker, to agentic coding, to hiring. And it's now on YouTube! It's also general enough that it should be interesting even to those not already knee deep in Rust π
www.youtube.com/watch?v=nOSx...
About a month ago, I gave a talk at the Rust Amsterdam meetup about Sguaba (the type-safe spatial math Rust crate), and the recording of that is now online for anyone who wants their head to hurt with frames of reference and coordinate transforms π
youtu.be/kESBAiTYMoQ