I test my code. But 32 years of experience told me in the first three that testing needs a second pair of eyes. Whatever blind spots I had in development I will have in writing tests; it is therefore imperative to have black box testers with no knowledge of the code to prejudice them. They work from a functional spec which—I am shocked!—has gone out of style with tat TDD junk.
Unit tests are a waste of time. They take a long time and usually only test standard scenarios, and tey requires design compromises that ghood developers don't make.
The problem is that nobody is allowed to concentrate now, so they do lousy work, and instead of going back to what worked, minimal interruptions
managers instead pile on new layers of process, wasting more time.
Abandon the fads, go back to minimal interruptions.