Your question is Ad Platform with Analytics. 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).
Design an advertisement platform that displays ads from various organizations and collects stats to determine which ads perform better or worse.
Asked in the System Design 2 stage. Focus on how you would serve ads, log impressions and conversions, and use feedback to improve ranking. Explain how you would handle delayed labels, attribution, and reporting accuracy.