A client’s team spent a full week adding a CSV export to their admin panel. Two engineers, clear requirements, maybe a day of actual work. The rest of the time went to understanding existing code well enough to change it safely. That’s what I call codebase drag: when the codebase makes every task take longer than it should. It doesn’t show up in any dashboard or sprint report.
I’ve seen many an old crusty system with good test coverage. Doesn’t mean it’s good and high coverage doesn’t mean a good test suite. Coverage doesn’t measure quality of assertions being made.
Good coverage is still a lot better than no coverage when doing changes in a project you haven’t touched in ages