Design a system to show the top 10 most frequently listened songs in the last 7 days

Focus on outlining the architecture of the system, including data sources, storage, and processing components. Discuss how you would collect and aggregate listening data, considering factors like user privacy and data retention policies. Explain the algorithms you would use to determine the top 10 songs, and how you would ensure real-time updates versus batch processing. Consider scalability and performance, particularly if the user base is large, and address how you would handle potential data inconsistencies. Finally, think about the user interface and how the results would be displayed to users.