Harness Engineering 101: Prompt Engineering wasn't enough. Neither was context. The harness was. (opens in new tab)

TL;DR Prompt engineering and context engineering both still left me as the bottleneck. I re-explained myself every single session. The fix was structural, not verbal. A harness: standing context, memory files, real account access, delegation, and skills, so the model starts every morning already knowing my work. The term got named in 2026 (Agent = Model + Harness). Two camps now argue about it and miss that they agree: the edge moved out of the model and into the structure around it. A harnes...