Your question is Refactoring Legacy Data Systems. 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 a legacy data system to improve performance. Explain the system's original limitations, how you evaluated competing technical options, and how you managed delivery risk while preserving data correctness. Focus on your individual ownership, collaboration with stakeholders, measurable results, and what you learned.