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G-J van Rooyen

@gvrooyen.com
94 followers 64 following 151 posts

Director: Engineering & Innovation @ octoco.ltd. Associate Professor Extra-Ordinary in Industrial Engineering @ Stellenbosch University. programming languages · trail running · innovation management · startups · good wine · business · reading

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G-J van Rooyen @gvrooyen.com · 19/09/2026
Thinking of starting a fried fish takeout named "Batter Call Sole"
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Bryan Cantrill @bcantrill.bsky.social · 06/12/2025
Your intellectual fly is open bcantrill.dtrace.org/2025/12/05/y...
bcantrill.dtrace.org
Your intellectual fly is open | The Observation Deck
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G-J van Rooyen @gvrooyen.com · 28/08/2026
After several years on #Neovim, I'm going to give #Helix a spin! I've heard good things about it; keen to try something new
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G-J van Rooyen @gvrooyen.com · 25/08/2026
No cheating. Share the last photo of the sky from your camera roll
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Katie Mack @astrokatie.com · 10/04/2026
As far as I know there is literally no reason for this, it is just an incredibly lucky coincidence that we get to enjoy for free
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sabine 🐫🦀 / "use ocaml"; @sabine.sh · 06/03/2026
trying this linkedinfluencer thing to say OCaml and Domain Specific Languages www.linkedin.com/pulse/domain...
linkedin.com
Domain Specific Languages as AI Supervision Gates
Everyone's talking about AI agents. Autonomous this, agentic that.
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David Shiffman, Ph.D. 🦈 @whysharksmatter.bsky.social · 04/03/2026
“Fish” can be both singular (one individual) and plural (multiple individuals of the same species.) “Fishes” is multiple species. 🐠 Fish 🐠🐠🐠 Fish 🐠🐡🐟 Fishes Now you know. And knowing is half the battle.
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G-J van Rooyen @gvrooyen.com · 26/01/2026
I've been thinking a lot about how coding agents can help us write more literate programs. gvrooyen.substack.com/p/literate-a...
gvrooyen.substack.com
Literate Agents
“We don’t really have any technical documentation in the data room yet, so you can just tell us what you need,” the CTO said.
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Simon Willison @simonwillison.net · 20/01/2026
This is great - it's about time someone updated the discourse on LLM energy usage to reflect that coding agents use massively more prompts than occasional questions to ChatGPT Simon estimates that a day of coding agent usage comes out close to the energy needed to run a dishwasher
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Steven (with a PH) @sjksalisbury.bsky.social · 27/12/2025
Please bring the card machine with you when you bring the bill. I had the pollo con spinaci, I didn't return the ring to Mordor. You don't have to split this interaction across multiple volumes.
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Andrew Turley @aturls.bsky.social · 02/11/2025
Look folks gen AI videos are out in the wild so if you weren't already being careful about sharing rage bait videos then now is a great time to start If you can't trace a video back to a trusted source then I recommend leaving it where it is, like a slice of bologna you found on the street
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Scott Hanselman 🌮 @scott.hanselman.com · 11/10/2025
Minor medical situation on the flight and it’s cool that my wife is able to jump up and help out when they ask for a licensed medical professional. One day someone will need a regular expression so I stay ready.
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Subscribe to Radio Free America (link in bio) @kleinman.bsky.social · 01/10/2025
RIP Jane Goodall, by all accounts a wonderful woman who loved this Far Side cartoon
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G-J van Rooyen @gvrooyen.com · 28/07/2025
With the sad passing of Tom Lehrer, a flashback to the place where I heard one of his songs for the very 1st time more than three decades ago
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Al Yankovic @alyankovic.bsky.social · 15/07/2025
nytimes.com
Weird Al Is Enjoying His Rock-Star Moment
At Weird Al Yankovic’s sold-out Madison Square Garden debut, pop culture’s foremost song parodist was feeling the love.
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G-J van Rooyen @gvrooyen.com · 07/07/2025
Had a vampire marathon this weekend with my son: Nosferatu (1922), Shadow of the Vampire (2000), Nosferatu (2024). Highly recommended watching order 🧛🏻
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Oliver Darkshire @deathbybadger.bsky.social · 27/06/2025
have been confused for days about insane cats invading our yard and destroying the plants for no reason only to find out I have accidentally planted fucking catnip all over the place, I am this neighborhoods feline drug lord, ive devasted their society
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G-J van Rooyen @gvrooyen.com · 21/06/2025
Rereading an old fantasy novel from my youth. The protagonist names are all bouba; the villains outlandishly kiki
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G-J van Rooyen @gvrooyen.com · 28/05/2025
Ek steel hierdie en maak dit "net hoed, geen stoet"
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G-J van Rooyen @gvrooyen.com · 25/05/2025
Love using plain chat as a scratchpad where I can back-and-forth with the AI until I get what I need (I've been desperate to turn my bank's old email statements into flexible machine-readable data for DECADES) and then just ask for a prompt that I can use in future or pass along to an agent
An LLM-generated prompt to give to LLMs. It describes the desired CSV structure, gives key instructions based on prior troubleshooting, and a clear description of the output artefact.
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Scott Hanselman 🌮 @scott.hanselman.com · 17/05/2025
The word “login” comes from throwing a log attached to a rope with knots overboard a ship to see how many knots go by over time (see also, knots as speed). You’d then put that info in the “log book.” You’d “log in” on a regular basis. This wasn’t from 1959, it was likely from 1689! Etymology baby!
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G-J van Rooyen @gvrooyen.com · 14/05/2025
This feels right out of Snow Crash. Read the wrong text and you might catch a serious mind-altering (or -destroying) neuro-linguistic virus. (It's thrilling! Like a new frontier still waiting to be tamed)
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G-J van Rooyen @gvrooyen.com · 13/05/2025
I'm unsure why Putin is looking so pissed about this
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Martin Fowler @martinfowler.com · 30/04/2025
NEW POST Even experienced developers fumble around when working with a new platform. Unmesh Joshi shows how using an LLM helped him learn how to use an unfamiliar toolset. martinfowler.com/articles/exp...
martinfowler.com
Building TMT Mirror Visualization with LLM: A Step-by-Step Journey
Notes from my Thoughtworks colleagues on AI-assisted software delivery
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Kevin M. Kruse @kevinmkruse.bsky.social · 25/04/2025
I’ve never had someone take a honk as a conversation starter before but there we are
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Kevin M. Kruse @kevinmkruse.bsky.social · 25/04/2025
Guy nearly hit me in traffic, so I honked at him. Next stop light, he pulls up next to me and rolls down his window. “You got somethin’ to say to me?!” “Yeah, I think you’re a shitty driver. That’s what the honk was for.”
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G-J van Rooyen @gvrooyen.com · 22/04/2025
Oblivion Remastered looks absolutely BEAUTIFUL. Can still vividly remember the anticipation 20 years ago, and the live reveal brings back all those feels
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G-J van Rooyen @gvrooyen.com · 19/04/2025
This court order is literature
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Katie Mack @astrokatie.com · 15/04/2025
An astronomy professor colleague of mine once relayed trying to explain to his students why it was important that they actually write their class reports themselves. “The point is not to teach ME about neutron stars,” he said.
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Oregon 🕎🎲 @oregonthedm.bsky.social · 09/04/2025
Biggest commitment to a 3 second joke I've ever seen
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G-J van Rooyen @gvrooyen.com · 09/04/2025
Why vim uses hjkl for movement, ESC to change modes, and why ~ represents the home directory in Unix. It's all thanks to the beautiful ADM-3A terminal that was born in the same year as me! catonmat.net/why-vim-uses... #retrocomputing #vim #neovim
catonmat.net
Here is why vim uses hjkl keys as arrow keys
I was reading about vim the other day and found out why it used `hjkl` keys as arrow keys. When Bill Joy created the vi text editor he used the ADM-3A terminal, which had the arrows on hjkl keys. Natu...
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G-J van Rooyen @gvrooyen.com · 05/04/2025
This is terrible. The 50% (!!) US trade tariff on Lesotho, who mainly manufactures jeans for brands like Levi's and Calvin Klein, risks wiping out half of their exports. www.news24.com/fin24/econom...
news24.com
Baffled Lesotho seeks to engage with US on jeans tariffs | Business
Lesotho scrambled to put together a delegation on Friday to head to Washington to engage with the US on tariffs that risk wiping out nearly half of its exports, its trade minister said, in what could ...
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eraldo.bsky.social @eraldo.bsky.social · 03/04/2025
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Existential Comics @existentialcomics.com · 31/03/2025
The Frog and the Scorpion From a Rational Point of View existentialcomics.com/comic/596
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Chris Roper @chrisroper.bsky.social · 26/03/2025
Excellent.
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G-J van Rooyen @gvrooyen.com · 20/03/2025
@thorstenball.com Empire of Pain was a terrific read. Keefe's ability to make a work of journalism and contemporary history read with the suspense of a spy novel is simply incredible. Even the afterword and "About the Sources" have plot elements!
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Kevin M. Kruse @kevinmkruse.bsky.social · 19/03/2025
I'm always tempted to stare intensely at them, nodding along as they talk. Scrawl a note and hold it up to them: DID BOB CLEAR THIS WITH LEGAL??? WHAT ABOUT HR????
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Yaron Minsky @yminsky.bsky.social · 19/03/2025
I quite liked this short post on "vibe coding"vfrom @simonwillison.net. It captures both the joy and the limitations of the approach.
simonwillison.net
Not all AI-assisted programming is vibe coding (but vibe coding rocks)
Vibe coding is having a moment. The term was coined by Andrej Karpathy just a few weeks ago (on February 6th) and has since been featured in the New York …
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Thorsten Ball @thorstenball.com · 19/03/2025
Claude when I write "but it doesn't work, does it?"
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Thorsten Ball @thorstenball.com · 18/03/2025
Sounds like C. S. Lewis didn't use MX Blues andynaselli.com/the-collect...
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G-J van Rooyen @gvrooyen.com · 17/03/2025
@kevinmkruse.bsky.social Feels as if I'm seeing leaders doing the PW Botha finger quite a lot recently duckduckgo.com?t=h_&q=pw+bo...
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Wristy @wristroom.bsky.social · 19/02/2025
OUTSIDE of you, there are MILLIONS of wolves
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Charl P. Botha @charlbotha.com · 16/03/2025
I was looking for something exactly like this, and then HN delivered the news. Send any file from your computer directly to anyone else's computer #p2p via your browser (and WebRTC, so should go through firewalls). Transmitted files do not touch any server, only sender and receiver. file.pizza
file.pizza
FilePizza • Your files, delivered.
Peer-to-peer file transfers in your web browser.
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G-J van Rooyen @gvrooyen.com · 15/03/2025
What I adore about South Africa's constitution is how clear it is to understand. E.g. §2 sets out the powers of the President (Hi, Uncle C! 👋) and it's just so simple, direct, and democratic. The Prez has no authoritative powers (we've had enough of that). The director conducts, the orchestra plays.
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G-J van Rooyen @gvrooyen.com · 15/03/2025
I have the somewhat unusual problem that, if I leave the doors of the Octoco Group's registered office open after dark (even for a few minutes), large frogs creep in and nestle underneath the antique reed organ
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Alasdair Beckett-King @misterabk.bsky.social · 14/03/2025
Every mind-bending TV show:
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G-J van Rooyen @gvrooyen.com · 14/03/2025
It also turned Rand Merchant Bank into "R&B", so maybe that's a nice musical genre for some vibe marketing by FirstRand
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G-J van Rooyen @gvrooyen.com · 14/03/2025
The notetaking AI for my meeting transcribed Standard Bank (probably with an Afrikaans accent) as "Stunner Bank" and I think @standardbankza.bsky.social should just lean into it and rename
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Nick Rempel @nrempel.com · 13/03/2025
Good morning. Locking in.
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