Your question is Technically Challenging Project. 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 a technically challenging project. Focus on a specific project you personally contributed to or led. Explain the technical difficulty, your responsibilities, the decisions and trade-offs you made, how you worked with others, and the measurable outcome.