The Anatomy of Harness Engineering: How to Evaluate, Iterate, and Guard AI Coding Agents

Summary

Google published a blog post on harness engineering for evaluating, iterating, and guarding AI coding agents, noting that end-to-end benchmarks like SWE-bench are often expensive and slow.

Key facts

• Google Developers Blog published the post on 2026-10-03.
• The post covers evaluating, iterating, and guarding AI coding agents.
• It says end-to-end benchmarks like SWE-bench are often expensive and slow.

Why it matters

Teams building or buying AI coding agents get guidance on harness engineering, since broad benchmarks like SWE-bench can be costly and slow for iteration.