Joy & Curiosity #64
Interesting & joyful things from the previous week
I was live on Twitch this week, using Amp to hack on my little side- and toy-project terminal emulator. It’s written in Rust, barely has any third-party dependencies, and does its rendering using Metal and the GPU.
Without exaggeration (and I know it sounds like exaggeration, but hey, it’s not): this was some of the most magical stuff I’ve ever experienced with agents.
You can still watch the whole thing here. If you do, you’ll see how the agent figures out how to render background colors for terminal cells, how it then fixes the wrong struct alignment/padding of the data it sends to the GPU after I show it a screenshot, how it then builds a 2D renderer for box drawing characters, and a feedback loop, and then iterates based on screenshots to render curved and straight characters.
Or you can watch these two highlights: this one in which I guide the agent to build a feedback loop for itself, so it can “see” what the GPU renders; and then this one, in which the agent first uses the feedback loop to check which box-drawing characters aren’t rendered properly and then adds the code to render them.
Magical, truly. Rendering the characters — that’s one thing. But how it “understood” how the feedback loop should work and how it builds it — man, that was mind-blowing.
Claude Opus 4.5 was released. A week after Gemini 3 Pro.
We switched Amp to Opus 4.5, too. We switched after a lot of user feedback, and back and forth, and evaluations, and testing, and should-we? and could-we? and don’t-we-have-to? and it’s-so-good. There’s more in the post there and I encourage you to use it, but let me say this: I’m rethinking — again — the future of software development.
On a more practical level: I’m really fascinated by Anthropic’s Tool Search Tool. This does feel like something really useful. I’ve implemented it in Amp in less than an hour and have been playing around with it. There’s downsides (latency!), but I’m very intrigued.
This week I learned about expect(1) and pexpect, but, never having watched the movie, I don’t know what to make of this warning: “Don’t do this unless you like being John Malkovich”
Henrik Karlsson: “Today is my 1 year anniversary of being a full time writer on Substack. Some reflections.” Very interesting.
Speaking of, I’ve really come to enjoy reading through Substack notes. Here’s one by the very same Henrik Karlsson that I keep thinking of: “When I have low blood suger, or am in a bad mood because I haven’t exercised in a while, or have some other imbalance in my body, my mind will typically conjure some reason why I’m feeling that way; it will invent a story that explains why I’m feeling sad or frustrated. ‘I feel so trapped in my life.’ ‘X is so selfish.’ Etc. It is rarely productive to pay to much attention to those thoughts in the moment, since they are just made up stories, to explain a negative affect; giving them to much attention just makes my brain elaborate and come up with even fancier (and falser) stories for why I’m feeling bad.” It is incredible, isn’t it, to read something like that, in a feed. Like hearing a live orchestra when someone’s phone rings.
Benedict Evans in his latest newsletter: “Back to 1997: no one knows how this is all going to work. There are capital markets stories (even more for Coreweave and the other neoclouds), and chip stories, but the core I keep coming back to is the level of uncertainty around the actual applications - remember Yahoo, and Netscape, and Pointcast? i-mode and Blackberry? And meanwhile, Google didn’t exist yet and Mark Zuckerberg was 13. Bubble or no bubble, no one knows anything.”
And Benedict Evans has a new presentation out. Highly recommend flipping through it, as always.
Maybe I’m in a bubble and that’s why I don’t come across these types of posts very often anymore, but this one, Gunnar Morling’s On Idempotency Keys, was great and made me think of a lot of books and posts I read now many years ago.
What a read: Trillions Spent and Big Software Projects Are Still Failing. The subtitle — “AI won’t solve IT’s management problems” — already contains the clue that this is about “IT” and Big Software in Big Enterprises. That’s a world I’m very much not connected to (and it’s also interested that the world I am in doesn’t even get a mention) and it’s very, very, very interesting. Here’s one of many setup & punchline pairs that I could quote: “Phoenix project executives believed they could deliver a modernized payment system, customizing PeopleSoft’s off-the-shelf payroll package to follow 80,000 pay rules spanning 105 collective agreements with federal public-service unions. It also was attempting to implement 34 human-resource system interfaces across 101 government agencies and departments required for sharing employee data. Further, the government’s developer team thought they could accomplish this for less than 60 percent of the vendor’s proposed budget.” And the punchline: “Phoenix’s payroll meltdown was preordained. As a result, over the past nine years, around 70 percent of the 430,000 current and former Canadian federal government employees paid through Phoenix have endured paycheck errors. Even as recently as fiscal year 2023–2024, a third of all employees experienced paycheck mistakes. The ongoing financial stress and anxieties for thousands of employees and their families have been immeasurable.” But there’s so much more in there. I didn’t know about U.K. Post Office disaster and I had only read something short about the Lidl/SAP failure (“[…] three years of trying to make SAP’s €500 million enterprise resource planning (ERP) system work properly.”) Incredible stuff.
Weirdly enough, reading about these big IT projects reminded me of this 2018 Andy Greenberg article in Wired about the NotPetya attack on Maersk. Fantastic read: “All across Maersk headquarters, the full scale of the crisis was starting to become clear. Within half an hour, Maersk employees were running down hallways, yelling to their colleagues to turn off computers or disconnect them from Maersk’s network before the malicious software could infect them, as it dawned on them that every minute could mean dozens or hundreds more corrupted PCs. Tech workers ran into conference rooms and unplugged machines in the middle of meetings. Soon staffers were hurdling over locked key-card gates, which had been paralyzed by the still-mysterious malware, to spread the warning to other sections of the building.” I’m pretty sure that I read this when it came out and in the seven years since, I’ve thought of this scene many times: “When the tense engineers in Maidenhead set up a connection to the Ghana office, however, they found its bandwidth was so thin that it would take days to transmit the several-hundred-gigabyte domain controller backup to the UK. Their next idea: put a Ghanaian staffer on the next plane to London. But none of the West African office’s employees had a British visa. So the Maidenhead operation arranged for a kind of relay race: One staffer from the Ghana office flew to Nigeria to meet another Maersk employee in the airport to hand off the very precious hard drive. That staffer then boarded the six-and-a-half-hour flight to Heathrow, carrying the keystone of Maersk’s entire recovery process.”
Ethan Mollick on the Three Years from GPT-3 to Gemini 3: “Three years ago, we were impressed that a machine could write a poem about otters. Less than 1.000 days later, I am debating statistical methodology with an agent that built its own research environment. The era of the chatbot is turning into the era of the digital coworker. To be very clear, Gemini 3 isn’t perfect, and it still needs a manager who can guide and check it. But it suggests that ‘human in the loop’ is evolving from ‘human who fixes AI mistakes’ to ‘human who directs AI work.’ And that may be the biggest change since the release of ChatGPT.”
swyx on Agent Labs.
Compare: Bavarian Forest 2022 and Forests in Formation 2025. (If you like Factorio, you should also look at Stahlwerk and Chemiefabrik.)
According to this Harvard Business School paper, Acquired.fm (love them) now makes $2.5m per episode. They’re the best in the game, so: congratulations!
We’re Losing Our Voice to LLMs. I don’t use LLMs to write prose for me and can’t imagine ever wanting to, but lately, with Gemini 3 and now with Opus 4.5, what I’ve done is to hand them a collection of my writing that I want to emulate in a new thing and say “This is how I wrote, analyze the writing style.” They then come back with an eerily good analysis and then I tell them: “Imagine you’re Robert Gottlieb, how would you edit this?” And what they send back is not what I’d do, but it’s enough of a push to keep me rolling down the hill.
Beautiful personal website: alanagoyal.com
My ex-colleague Piotr, over at Zed Industries, wrote about making the project search in Zed a lot faster. Nerd-sniped: Project Search. That’s a great post. Perfect hook, carefully chosen code examples, great tone (“For a mix of reasons (including hubris), we never truly loved the idea of blindly going with ripgrep.”), good length. Now this is how it’s done.
Also, by the way, since we’re on the topic of Zed, I want you all to know that Zed’s editor/editor.rs has around 25k lines of code. It’s the heart of the editor. And guess what? It’s not a problem. Yes, it could be shorter, but also: it’s not a problem. I think working with that file has made me ignore every comment around lines of code for all eternity.
I’ve been meaning to write about how I changed my view on code reviews in the past two years, but then, while talking about it, Patrick sent me this post from the Raycast CEO and founder Thomas Paul Mann: no code reviews by default. It’s all in there. I’d sign every paragraph in there. Now, maybe the thing that I need to write is about how I changed my view on pull requests…
“This MacOS (APFS?) quirk was mentioned at the pub last night, and I still cannot believe this actually works when I tried it myself”
“‘Everything’ is search engine that locates files and folders by filename instantly for Windows. Unlike Windows search ‘Everything’ initially displays every file and folder on your computer (hence the name ‘Everything’). […] ‘Everything’ only indexes file and folder names and generally takes a few seconds to build its database. A fresh install of Windows 10 (about 120,000 files) will take about 1 second to index. 1,000,000 files will take about 1 minute.”
I had no idea that Charli xcx had a Substack, but apparently she does and this post I found very good: The realities of being a pop star. It’s weird, isn’t it, how odd it feels when an artist crosses from one medium to another like that, but when you say it out loud, it does seem obvious. “All my favorite artists are absolutely not role models nor would I want them to be, but maybe that’s just me. I want hedonism, danger and a sense of anti establishment to come along with my artists because when I was younger I wanted to escape through them. I don’t care if they tell the truth or lie or play a character or adopt a persona or fabricate entire scenarios and worlds. To me that’s the point, that’s the drama, that’s the fun, that’s the FANTASY.”
Benjamin Anderson: “This is what I’m calling technical deflation: it’s getting easier and easier for startups to do stuff, and this seems likely continue at least for the next few years. (Importantly, this is true regardless of whether you think pretraining or RLVR have “hit a wall”—improvements on speed, cost, context length, tool use, etc. are all sufficient to keep the trend going.) So what are the consequences of technical deflation?”
Oh do I love these indicators in the Quake Engine! Give me all the indicators!
“If you physically need gear to do the thing, start with cheap gear and keep research to the minimum. As a beginner you can’t percieve most of the differences between similar tools. Perceptual ability and taste only develop as your skills improve.” Having had GAS in multiple different hobbies, this one of the best things said about it.
My wife and I are watching our way through Variety’s 100 Best Comedy Movies of All Time and on Friday we saw Eddie Murphy’s Raw. I’ve seen bits of Raw many times over the years, but never the whole thing and, man, he was so good. So good. (Good pairing: I saw Being Eddie on the plane last week and it sets up the hype around Eddie in the 80s really well, but Raw then manages to match and surpass the hype.) I also asked ChatGPT to create a spreadsheet of the list, so, here you go.
