Your question is Resolving a Tough Coding Problem. 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).
Explain a time where you had a tough coding problem and how you went about solving it. Focus on a specific problem you personally owned, how you clarified the requirements, and how you evaluated possible solutions. Explain the debugging, testing, collaboration, and tradeoffs involved. The interviewer is looking for structured problem solving, persistence, technical judgment, and ownership of the outcome.