Your question is Refactor for Performance Gains. 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).
Describe a situation where you had to refactor code to improve performance. Explain what made the existing implementation a problem, how you determined the right refactoring approach, and how you evaluated the result. Focus on your individual ownership, the trade-offs you considered, and how you balanced performance improvements against correctness, maintainability, and delivery needs.