Your question is Project You Owned End-to-End. 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).
Tell me about one project you worked on that best represents your engineering strengths. Walk me through what the problem was, what you personally owned, how you prioritized the work when trade-offs came up, and what measurable impact it had.