Engineering investigations
Correctness and reliability
What happens when something runs twice, fails, times out or happens in the wrong order, and whether people can tell a stand-in value from the real one.
- Safe to run twice?PromptFinds actions that do damage when they run twice: double sends, double charges, duplicate rows.
- Fallbacks that look like real dataPromptFinds screens that show a confident zero or an empty list when the real answer is 'we could not load this'.
- Rules the data never enforcesPromptFinds the rules everyone assumes (one owner per task, no negative balance) that nothing actually checks.
- Dates, times and time zonesPromptFinds the date bugs that show up twice a year, at midnight, or in another time zone.
- Updates that overwrite each otherPromptFinds updates that overwrite newer data because two things wrote at once.
- Half-finished failuresPromptFinds what is left behind when something fails halfway.
- Lost place: Back, refresh and shared linksPromptFinds the everyday friction where Back closes the wrong thing, a filter resets, or a pasted link opens the wrong view.