For [a product], the single
metric that shows it's genuinely
working — not a vanity number —
plus two guardrails revealing if
I'm improving it by making the
product worse.

Pick the One Metric to Watch

One metric, with guardrails against gaming it.

Prompt

For [a product], propose the single metric that best indicates it's genuinely working — not a vanity number — plus two guardrail metrics that would reveal if I'm improving the first one by making the product worse.