Architect

May 3, 2026 · Artificial Intelligence

Why the Same Model Feels Different in Coding Agents: Model Sets the Capability Ceiling, Harness Sets the Production Floor

The article examines how a model defines an agent’s ultimate capabilities while the harness determines its production reliability, detailing continuous evaluation, context‑budgeting, tool‑error classification, multi‑model migration, and SRE‑style engineering practices needed to keep AI coding agents stable and performant.