"We're spending about five figures a month on coding agents. I think it's making the team more productive. I'm not sure. But I think." That's from a VP of engineering running a team of ~100. It's obvious that coding agents are faster than human engineers, but it's not obvious how you manage your spend. For decades, the constraint on shipping software was headcount. You had N engineers, you pointed them at the highest-priority work, and you shipped what you shipped. Today you can spend 2-3x the cost to produce the same software in a tenth of the time. The recent port of Bun from Zig to Rust took 11 days and $165k in API costs. That's obviously a net improvement over what it would have cost to have engineers do it by hand, but choosing to do that requires a new calculus. Because faster production is not the same as better economics. The fact that you can generate more code, faster, doesn't mean you should. Every task is now a choice: which model, how much speed, how much accuracy, how much human guidance. Get those parameters wrong and you pay a lot of money to build the wrong thing very fast. The challenge for engineering teams has always been picking the right things to build. Agents didn't fix that problem — it's faster but just as expensive:

Two years ago, @profjoeyg and I wrote that open models wouldn't catch the frontier — but that it didn't matter. That's more true than ever today. The whole debate is framed around the wrong question. Everyone keeps asking whether open models will beat GPT or Claude on evaluations. But almost nobody building real applications needs the single best model in the world for every task. They need a model that's smart enough, fast enough, and cheap enough — running where they can count on it. That's a much lower bar, and open models cleared it a while ago. As access to frontier models gets more complicated for application builders, "close to frontier and fully under my control" starts to look like the better deal, not the consolation prize. GLM 5.2 landing in Cursor is the kind of signal that makes this concrete — a model you can actually reach for, not a benchmark you admire from a distance. The frontier labs will keep selling the best top-end model. That was never the contest worth winning for most of us. Smart enough, fast enough, cheap enough is good enough: