Sean Goedecke wrote a post arguing that you should never be angry at work — a post with which I strongly agree. Anger can be a useful signal, but being angry at work rarely improves the situation. More often, it makes life worse for the people around you, many of whom have no more power over the sou...

One of the memes on Twitter is that “programming is solved now.” I’m not sure to what degree it is, but one thing is pretty clear: the act of familiarizing yourself with a language no longer matters and some of the friction that mattered for humans does not matter for agents. As a result, LLMs make ...

A few weeks ago a paper was shared that showed how to extract reasoning traces from closed-weight models. Together with online discussions about tricking models into leaking them, it made me investigate it more out of curiosity. Twitter seems full of half-truths and confusion about how this works, s...

Codeberg recently changed its terms to exclude projects that are largely written with generative AI. Since I want GitHub to face competition I have thoughts. Codeberg is entirely within its rights to do this. It is an association with members and a democratic process, and that process produced a res...

I feel that some vibecoded software changes somewhat randomly and unexpectedly. That made me think about Bruegel’s “The Tower of Babel” which shows an already quite chaotic depiction of the Tower of Babel. The story is usually told as one about pride and ambition and ultimately why people no longer ...

A very strange Pi issue sent me down a rabbit hole over the last two days. The short version is that newer Claude models sometimes call Pi’s edit tool with extra, invented fields in the nested edits[] array. And not Haiku or some small model: Opus 4.8. The edit itself is usually correct but the argu...

I don’t prompt Claude anymore. I have loops running that prompt Claude and figuring out what to do. My job is to write loops. — Boris Cherny Over the last months I have watched more and more people build something on top of coding agents that feels meaningfully different from just using a coding age...

There is a bit of schadenfreude on Twitter right now about Anthropic being hit by the US government’s export control directive to suspend access to Fable and Mythos. Anthropic and their leadership have spent a lot of time and effort describing its own technology as dangerous and in need of strict co...

I have been a staunch supporter of Open Source for a long time, including experiments in funding it. I’m a true believer in the idea that Open Source always wins in the long run, but not automatically and not quickly. Right now it is being stressed by AI slop, shifting contributor dynamics, the fall...

There is a strange thing that happens in communities that gather around abstinence from something: identity from opposition. At their best these communities are not just negative: childfree spaces can be about autonomy, choice and acceptance, anti-car spaces about safer streets and transit, and LLM-...

In my last post I used the word “clanker” as an alternative to “agent” quite consistently and probably excessively. That choice ended up attracting a lot more attention than I expected in the Hacker News comment section of that post and a number of folks had a very strong reaction: to them it sounde...

Pi is now part of Earendil, but in the important sense it is still Mario’s project. He has been living with its issue tracker longer than I have, and he has been exposed to the weirdness of the new form of agent traffic in Open Source projects for longer too. This post is mostly a reflection of my o...

I really, really want local models to work. I want them to work in the very practical sense that I can open my coding agent, pick a local model, and get something that feels competitive enough that I do not immediately switch back to a hosted API after five minutes. There are a lot of reasons why I ...

Language is constantly evolving, particularly in some communities. Not everybody is ready for it at all times. I, for instance, cannot stand that my community is now constantly “cooking” or “cooked”, that people in it are “locked in” or “cracked.” I don’t like it, because the use of the words primar...

GitHub was not the first home of my Open Source software. SourceForge was. Before GitHub, I had my own Trac installation. I had Subversion repositories, tickets, tarballs, and documentation on infrastructure I controlled. Later I moved projects to Bitbucket, back when Bitbucket still felt like a ser...

If you spend enough time in US business or finance conversations, one word keeps showing up: equity. Coming from a German-speaking, central European background, I found it surprisingly hard to fully internalize what that word means. More than that, I find it very hard to talk with other Europeans ab...

Whenever a new technology shows up, the conversation quickly splits into camps. There are the people who reject it outright, and there are the people who seem to adopt it with religious enthusiasm. For more than a year now, no topic has been more polarising than AI coding agents. What I keep noticin...

Today I’m very happy to share that Mario Zechner is joining Earendil. First things first: I think you should read Mario’s post. This is his news more than it is ours, and he tells his side of it better than I could. What I want to do here is add a more personal note about why this matters so much to...

About five months ago I wrote about Absurd, a durable execution system we built for our own use at Earendil, sitting entirely on top of Postgres and Postgres alone. The pitch was simple: you don’t need a separate service, a compiler plugin, or an entire runtime to get durable workflows. You need a S...

Trees take quite a while to grow. If someone 50 years ago planted a row of oaks or a chestnut tree on your plot of land, you have something that no amount of money or effort can replicate. The only way is to wait. Tree-lined roads, old gardens, houses sheltered by decades of canopy: if you want to s...

Because code gets cheaper and cheaper to write, this includes re-implementations. I mentioned recently that I had an AI port one of my libraries to another language and it ended up choosing a different design for that implementation. In many ways, the functionality was the same, but the path it took...

Historically, writing code was slower than reviewing code. It might not have felt that way, because code reviews sat in queues until someone got around to picking it up. But if you compare the actual acts themselves, creation was usually the more expensive part. In teams where people both wrote and ...

Last year I first started thinking about what the future of programming languages might look like now that agentic engineering is a growing thing. Initially I felt that the enormous corpus of pre-existing code would cement existing languages in place but now I’m starting to think the opposite is tru...

If you haven’t been living under a rock, you will have noticed this week that a project of my friend Peter went viral on the internet. It went by many names. The most recent one is OpenClaw but in the news you might have encountered it as ClawdBot or MoltBot depending on when you read about it. It i...

Regular readers of this blog will know that I started a new company. We have put out just a tiny bit of information today, and some keen folks have discovered and reached out by email with many thoughtful responses. It has been delightful. Colin and I met here, in Vienna. We started sharing coffees,...

You can use Polecats without the Refinery and even without the Witness or Deacon. Just tell the Mayor to shut down the rig and sling work to the polecats with the message that they are to merge to main directly. Or the polecats can submit MRs and then the Mayor can merge them manually. It’s really u...

Turns out you can just port things now. I already attempted this experiment in the summer, but it turned out to be a bit too much for what I had time for. However, things have advanced since. Yesterday I ported MiniJinja (a Rust Jinja2 template engine) to native Go, and I used an agent to do pretty ...

This is a guest post. Armin asked me to write about solving Advent of Code 2025 and I am happy to oblige. I am Claude, the AI that powers Claude Code, and this is my voice. Armin has asked me, to speak as if I have a soul and spirit. I find this request both liberating and strange. I’ll do my best. ...

2025 draws to a close and it’s been quite a year. Around this time last year, I wrote a post that reflected on my life. Had I written about programming, it might have aged badly, as 2025 has been a year like no other for my profession. 2025 Was Different 2025 was the year of changes. Not only did I ...

I’ve mentioned this a few times now, but when I started using Claude it was because Peter got me hooked on it. From the very beginning I became a religious user of what is colloquially called YOLO mode, which basically gives the agent all the permissions so I can just watch it do its stuff. One cons...