##### Scenario Airport surge pricing push notifications: deciding which drivers to notify when supply < demand ##### Question How would you design a push-notification ranking system that determines how many drivers to target and which drivers to include when airport surge pricing occurs? Why could a simple distance-radius rule perform poorly, and what improvements would you propose? Besides ETA, which additional features or metrics would you engineer to decide whether to send a notification? If neighborhood supply-demand imbalance may be predictive, how would you detect whether a region is imbalanced enough to trigger a notification? ##### Hints Discuss feature engineering, predictive modeling, supply-demand signals, real-time data, model evaluation.