What Is Harness Engineering? A Hands-On Introduction

Harness engineering is the essential skill for building operational AI agents by creating systems around a core large language model. This "harness" consists of components like memory, tools, planning, and action capabilities that guide the agent's behavior. The future of engineering is shifting from writing code to designing these complex harnesses that enable AI to solve problems autonomously. The content introduces foundational primitives for this work, beginning with workflow design, also known as "loop engineering." It then details specific patterns such as ReAct, Plan-then-Execute, and Reflexion as core building blocks for robust agent systems.