Ideally you'd run tests both in staging (first) and production (only if staging says OK), with the goal to catch 99.99% of issues in staging, safely away from t

Ideally you'd run tests both in staging (first) and production (only if staging says OK), with the goal to catch 99.99% of issues in staging, safely away from the paying end users. Because realistically, something will go wrong sooner or later and it will cost the company (and its customers) a lot more money and reputation if it happens in the user-facing environment.