Driving the Agent Quality Flywheel from Your Coding Agent

Engineering agent quality, not vibe-checking itYou've shipped an agent. It works. You tweak a prompt to fix the one thing a user complained about, and it looks better on the three examples you tried. The question that keeps you up at night: did I just break ten others?That gap, between "looks better on a few examples" and "actually better in production", is the daily reality of building agents. Most teams have eval cases somewhere. Most teams tweak prompts. Few connect the two with enough discipline to know whether a change moved the metric or just moved the vibe.The scariest failures aren't the loud ones. They're the agents that look like they're working (confident answers, a plan that reads fine) while quietly getting the user's actual goal wrong.

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Excerpt limited to ~120 words for fair-use compliance. The full article is at Google Developers Blog.