Beginner question: how do you check if your agent got worse after you change something?
A student building small AI automations asks how to detect regressions after changing a prompt or model. They already collect messy real inputs and self-grade pass/fail. The thread's key advice: freeze a fixed test set of 15-20 realistic inputs and rerun the exact same set after every change — 'run it a few times and squint' measures vibes, a fixed set measures proof.