The Answer to the Harness Question

Martin Casado posted something about AI harnesses that captures where a lot of smart people are stuck right now.Loading tweet... On harnesses, I vacillate between three beliefs: the less harness, the better. Models are the magic. Post training a model and harness is dramatically better and the model providers win. Harnesses have real independent value from the model. I have no idea which is right. Martin CasadoI think I can answer this.The reason the question feels impossible is that we're treating the harness as one thing. It's actually two. Every harness carries some mix of WHAT and HOW—context about what you want, and instructions for how to get it. And those two halves age in opposite directions.The HOW half rots. This is Sutton's Bitter Lesson playing out in your config files: the smarter models get, the dumber your step-by-step instructions look by comparison. If your harness is mostly HOW, then Martin's first belief is correct. Less harness is better, because the model is the…