The "You Don't Know What You Don't Know" Bug
There’s a class of bugs that took me a long time to recognize because they don’t look like bugs at all. Nothing crashes. Nothing fails tests. Nothing even looks wrong. And yet, a critical assumption about the system is no longer true. These are the bugs that happen when a guardrail is silently removed—intentionally or accidentally—and the system keeps working as if nothing changed. I’ve started thinking of these as “you don’t know what you don’t know” bugs. ...