Architecture & practice·Judgement and reasoning traps
the design covered what happens when it works and the review found nothing about what happens when the vendor is down.
Happy path thinking
Also calledhappy path, sunny day design
Designing, estimating and demoing only the case where everything succeeds. It is the default mode of thought and it is where most of the missing work in an estimate hides, since error handling, retries, partial failure and reconciliation are usually the larger half. The reliable prompt in a review is to ask what happens when each external thing is slow, absent or wrong.