This document describes Facebook-style notifications using HBase and event streams. It discusses capturing user intent from actions like browsing, buying, and registering on ecommerce sites. Notifications are pre-created in real-time by intersecting user intent data with product change events in HBase. The solution uses technologies like Trooper for event processing, Phantom as a reverse proxy, and Flipcast for multi-cast notifications. It provides low-latency access to notifications while scaling to handle large volumes of user, product, and event data.