Your question is Design a Personalized Notification Ranker. 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).
You are building a notification system for a consumer app. The product sends many possible pushes, such as order updates, offers, reminders, and re-engagement messages, but users should receive only the most relevant notifications at the right time.
How would you design a Notification System?