Most expensive bugs are predictable in hindsight. The fix is usually straightforward; the detection timing is the real problem.
My default approach is to ask, “Where will this fail quietly?” before I ask, “How do I implement this quickly?” Quiet failures are the ones that pass tests and still create bad outcomes.
Three checks I run by default
- Input boundaries: what is malformed but still technically valid?
- State transitions: what happens when steps are retried or partially completed?
- Observability: can we see the failure from logs and metrics without manual forensics?
The goal is not paranoia. The goal is reducing avoidable operational load later.
Why this matters
Catching one issue in design review can remove weeks of low-quality firefighting. It also keeps team trust high because release quality feels intentional instead of lucky.