I had 87% coverage, and we still broke the billing flow on launch day.
Not because of a gap in the percentage. Because 87% was covering the wrong things. The tests were written to pass a gate, not to catch a failure.
That is a more common story than most teams admit. And the reason it keeps happening is not that engineers are careless. It is that the incentive structure you created made it the rational outcome.
The series checkpoint
The first three articles in this series built the investment case for testing and then dismantled the received wisdom about how to execute it. We've made the economic argument for automation. We've restructured when quality checks happen across the SDLC. We've replaced the pyramid model with something shaped by risk rather than by code hierarchy.
