Code coverage measures what code your tests execute, not what they verify. 100% coverage with weak assertions is worse than 60% coverage with strong assertions on critical paths. Focus on meaningful assertions, not percentages.
Strong answers go beyond line and branch coverage: risk-based coverage, user journey coverage, requirement coverage, boundary value coverage, and negative scenario coverage. Best candidates discuss why high code coverage can be misleading (testing getters and setters versus testing business logic) and how they prioritise where to add coverage.
Tests quality thinking maturity. Candidates who chase coverage percentages without considering what they are testing are optimising the wrong metric. Those who think about meaningful coverage test smarter.