Many teams still test their software by having a person click around in a staging environment and report bugs back. Or by a developer doing the same thing in a local environment. This has always been a bad practice. It's becoming an untenable one. For a long time, the case for an automated test suite was a productivity argument. You could ship without tests (plenty of companies did, plenty still do) but you paid for it in slower iteration, scarier deploys, longer regression cycles, and the slow accretion of fear around the parts of the codebase nobody wanted to touch. Manual QA worked, in the sense that it caught some bugs some of the time. It just didn't scale: every new feature meant a longer test plan, every release meant a longer freeze, and every refactor was a gamble. Then agents started writing meaningful amounts of the code. What changes when code volume goes up A coding agent will happily produce more code in an hour than a developer used to ship in a week.…