Hamel Husain argues that AI product failures usually stem not from the model but from the surrounding system, or harness. Every working AI product needs clear instructions, unbreakable rules, and feedback loops to verify outputs. Husain released a free Claude Code skill that helps agents test and catch mistakes he's seen across 50+ companies.
If you're building an AI product and it's not working the way you want, the problem probably isn't the AI. It's everything around it. OpenAI just published a paper on this. 3 engineers built a million-line app with zero human-written code. Their biggest finding? Improving the environment around the AI mattered more than improving the AI itself. They call it the harness. Clear instructions so the AI knows what to do. Rules it can't break. And most importantly, feedback loops so the AI can check whether its own output output is actually working. The last part is the hard one. Is your AI product giving good answers? I released a free skill you can install in Claude Code. It guides your agent through testing your AI and catches the common mistakes I've seen after helping over 50 companies. Comment harness and I'll send a link.
