Topic
Deliberately breaking an endpoint to pin down which layer changed, and maintaining a rerunnable suite across dependency upgrades.
A reconstructed postmortem on dev.to has a merge bot posting eval=pass from a markdown summary, and its proposed replacement scores git diff only, with a contract test that keys on four directory names.
Reality
Offset paging passes a static test suite and then skips rows the moment a merchant inserts a product mid-read. A dev.to case study answers that by freezing the sort key, tie-breaker and error codes in a spec file the agent cannot edit.
Reality
A team switched LLM providers on a better eval score and lost three days to a field name. The published fix is sound; its own test suite argues with itself.
Reality
A renamed field cost one team a P1 three days after a four-minute code review. Splitting breaking-change diffs from linting from consumer contracts makes most of the tooling debate disappear.
Reality
A walkthrough breaks one guarded Prisma endpoint on purpose and shows why the response alone never tells you whether shape, validation, query arguments or projection moved.
Reality