TL;DR — Analytics Pipeline

Design a real-time analytics pipeline that ingests billions of events per day from web and mobile clients, processes and aggregates them in near-real-time, and serves dashboards and ad-hoc queries with low latency. Think of systems like Google Analytics, Mixpanel, or Amplitude. Key features: Ingest events from web, mobile, and server-side SDKs. Real-time dashboards showing metrics within 30 seconds of event occurrence.