Harness Engineering: Why Your AI Coding Setup Matters More Than the Model

I have tech friends, good developers, who tried Claude Code or Cursor or Codex. They gave it a task, it wrote some code, the code was wrong, and they told me &ldquo;AI coding doesn&rsquo;t work.&rdquo; I hear this a lot. But I use Claude Code every day. It writes code, runs tests, manages my git workflow, plans my day, helps me prepare debates . We&rsquo;re using the same models. So why are our…