Dev.to
7/11/2026

The original title is "Your New Prompt 'Feels' Better. That's Not an Eval."
Original: Your New Prompt 'Feels' Better. That's Not an Eval.
Short summary
The post argues that eyeballing a few hand-picked examples to validate prompt changes is confirmation bias, not evaluation. It recommends building a 20-50 row eval set with input/expected-output pairs, scored automatically the same way each time, and re-run on every future change to catch regressions. The framing is aimed at AI interview prep, with heavy promotion of the author's paid prep sessions.
- •Hand-picked examples are confirmation bias, not evaluation — build a 20-50 row eval set
- •Score outputs automatically: exact match for structured output, similarity/grounding for open-ended text
- •Re-run evals on every future prompt or retrieval change to catch silent regressions
Generated with AI, which can make mistakes.
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