Module Overview: Real-Time Systems

"Design a system that updates users in real time."

This module covers real-time patterns: event streams, fanout, ordering, backpressure, and operational trade-offs.

Learning Goals

• Choose between polling, webhooks, and streaming
• Model event-driven architecture with clear boundaries
• Reason about ordering, retries, and idempotency
• Design for latency, throughput, and cost simultaneously

Interview Preparation

• ✅ Explain push vs pull trade-offs
• ✅ Discuss pub/sub, partitions, and consumer groups
• ✅ Handle retries, duplicates, and ordering guarantees

Real-World Application

• Notifications and activity feeds
• Realtime dashboards and collaboration
• Streaming pipelines and event processing

Estimated Time

45-60 minutes (includes practice)

Checklist

• Can explain polling vs push vs streaming
• Can model event streams and consumers
• Can design idempotent handlers and retries