Your question is Quality and Testing Strategy. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
How do you ensure high code quality, and what is your approach to writing effective unit and functional tests?
Explain how you balance design practices, code review, static analysis, test coverage, and continuous integration. Distinguish unit, integration, functional, and end-to-end tests, including when each is appropriate and how you keep tests reliable and maintainable.
Keep the answer language and framework agnostic, but include one concrete example from a full-stack application.