Stop Tuning Prompts. Build a Harness.

Anthropic shipped a piece earlier this month called How Claude Code Works in Large Codebases. I have not read anything more useful about coding agents this year. The core claim, in their words: “the ecosystem built around the model—the harness—determines how Claude Code performs more than the model alone.” In my phrasing: in a real codebase, the model is the smaller variable. The layer of context and tooling you wire around the agent matters more than which version of Sonnet or Opus is behind it.
The post stays high-level, which is the right move for a launch piece. What I want to do here is land it. Same seven pieces, but with the wiring you would actually put in a repo, in the order I would put it.









