Does Your Test Suite Actually Test Anything?
You have 100% code coverage. Every line is executed. The CI badge is green. Then you refactor a condition from > to >=, and not a single test fails. Your tests ran the code, but they didn't verify it.
Code Quality
How long do your architecture rules last without enforcement?
At the start of a project, you lay down grand principles: "the Domain never imports the Application layer", "Controllers do not access repositories directly." Three months later, an import slips through, nobody notices, and the boundaries fade away.