Your question is Real-Time Notifications From Queries. 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 a notification system that alerts users in real-time based on complex, user-defined search queries over a streaming data source at Peregrine Technologies.
Clarify requirements and scale before proposing an architecture. Address query evaluation, stream processing, notification delivery, persistence, reliability, and any ML components that improve relevance or suppress noisy alerts.