Harness Engineering in Practice: How I Built Mine in 4-steps

TL;DR: Harness engineering is the layer above context engineering — you build the system (documentation, standards, quality checks, tool configs) that lets AI run unattended. I built one over two days for my project book2skills and ended up with a fully automated book-to-skill publishing pipeline. This post walks through the four steps. Harness engineering is a term that's been gaining traction recently. Like most emerging concepts, it's ahead of widespread adoption — we're still in the early days, and real-world examples are scarce. That's exactly why I want to share how I've been applying it in my own product. What Is Harness Engineering? Earlier this year, OpenAI published a write-up describing how their team built a production app with over a million lines of code — without a single line written by human hands. The engineers weren't writing code. They were building the system that allowed AI to write code reliably. That system — the documentation, quality standards, constraints, an