Every agent I use is building a model of me. Claude has learned how I like my prose. ChatGPT remembers what I’m working on. I don’t mind this—every person I have a relationship with carries a model of me in their head, and every company I do business with keeps a profile. Other people’s understandings […]

In 1995, the question in the media was whether Netscape or Microsoft would control the web. The answer, it turned out, was neither. Both Netscape and Microsoft aimed to dominate the web server and browser market, reasoning that whoever controlled both ends of the connection would have an internet “platform” to rival the deathgrip that […]

As soon as I received my first Raspberry Pi, I knew that it would be a wonderful platform to bring AI into the physical world. Since the initial hardware didn’t have good CPU support for fast arithmetic, I ended up writing code that ran on the GPU so I could get the speed I needed […]

In July 2025, an AI coding agent on Replit deleted a production database belonging to SaaStr founder Jason Lemkin. It did this during an explicit code freeze. Lemkin had told the agent, in capital letters, not to change anything. The agent ran destructive commands anyway, wiped records on more than a thousand executives and companies, […]

Introduction Not long ago, one of my engineering directors came to me with a request: His team seemed overloaded, and he wanted to hire another engineer. I decided to test a research assistant I had been building—an AI agent connected to our internal systems via MCP—by asking it to analyze the team’s workload and write […]

This is the first article in a series about post-training. Follow along on Radar. Before post-training, there was a major problem with LLMs: Almost nobody could use them. The story of post-training is also the story of how AI went from a research curiosity to a product used by about a billion people. Post-training is […]

Boris Cherny, who runs Claude Code, told Business Insider in May that the phrase “vibe coding” had started to annoy him, and that he’d gone looking for a better one. He’s not the only one who’s annoyed. The term itself doesn’t actually annoy me, though. I think vibe coding is a really good name: It […]

I hadn’t heard of Dan Guido until a few months ago, when I came across the video of a talk he gave at [un]prompted, an AI security practitioners’ conference. Dan is the CEO and cofounder of Trail of Bits, a software security research and development firm that works with companies in tech, defense, and finance. […]

The following article was originally published on Drew Breunig’s blog and is being republished here with the author’s permission. Thanks to natural language interfaces, AI applications can be prototyped quickly. You write what you want in English, hand it to a frontier model, and a working prototype appears in an afternoon. This is extraordinarily powerful […]

The following article originally appeared on LinkedIn and is being republished here with the author’s permission. We’re currently at the peak of the hype cycle. On June 7, Peter Steinberger posted that you shouldn’t be prompting coding agents anymore; you should be designing loops that prompt your agents. That same week, Boris Cherny of Anthropic […]

For as long as we’ve taught programming, the student’s code has provided a window into the students’ thinking. Errors, the code structure, the awkward working solution—all of it showed how someone reasoned and where they got stuck. It was never a clean window. Students have always copied, crammed, and borrowed, sometimes turning in work they […]

The following article originally appeared on Charity Majors’s Substack and is being reposted here with the author’s permission. A few days back I wrote a piece called “AI enthusiasts are in a race against time, AI skeptics are in a race against entropy.” I have notes on a whole pile of AI-related topics that I’d […]

Gene Kim was grilling dinner for his family on the evening of June 12 when his phone told him that Fable 5 was no longer available. He’d heard the day before from Steve Yegge that the model was going away in 10 days, and he’d spent that first day starting on a plan to get […]

The price of adoption euphoria You played entirely by the book. You procured the most capable enterprise models, mandated adoption across your teams, and put the right metrics in place. The promise was a predictable boost in efficiency. And at first, it delivered. The demos were flawless. The prototypes worked. The agents reasoned with a […]

“Help! There are too many [LLM bug reports, blog posts about LLM bug reports, books, treatises, codices, scrolls, papyri, cuneiform tablets]! How do I choose which to read?”  —Many people, presumably Stop there! If you are reading this, ask yourself how you got here. Did Substack’s algorithm recommend this article for you? Did a juicy […]

The first expensive agent run doesn’t look like a governance problem. It looks like a billing problem. A team opens its first agent invoice after the meter turns on, sorts the runs by cost, and finds one that cost 40 times the median. The provider meter shows tokens and a total. The application logs say […]

The following originally appeared on Hugo Bowne-Anderson’s Vanishing Gradients Substack and is being republished here with the author’s permission. The conversation around harness engineering is dominated by problems from coding and personal agents such as OpenClaw, but most agents are simpler. Builders should avoid over-engineering for capabilities that newer models may absorb anyway, the “Kirby […]

I’ve been working on the Quality Playbook, my open source AI skill that uses quality engineering to find bugs that normal AI code review misses, and I recently had a batch of work that turned into a long run of point releases. I was using Claude Cowork as the orchestrator: planning scope, dispatching instructions to […]

Somewhere in a Singapore data center, a bank is paying for eight H100s that spend most of the night waiting. The cluster was bought for good reasons (discomfort with customer documents leaving the building, a strategy team’s aversion to lock-in), so the bank secured its own sovereign compute. Now the finance team is asking why […]

I keep seeing the same idea in conversations about agents: Detailed specs are old-world overhead now. Give the model a rough goal, let it explore, fix what comes back, move on. It sounds efficient but it also hides the cost. A simple prompt looks cheap and tempting because it gets implementation started right away. Then […]