Real-time + pub/sub
Live Wire
Real-time systems — sockets, streams, and the live data your phone never stops receiving.
Every chat app, live sports score, push notification, and real-time dashboard belongs to the same category of system: a broker fans messages out from publishers to many subscribers, in something close to real time. These activities make the mechanics visible — the fan-out pattern, the queue depth that grows when a consumer is too slow, the disconnect-and-replay dance that decides whether your inbox catches up or silently loses what it missed.
Drive publishers, watch a broker fan messages out to subscribers, and surface the dynamics that wreck real-time systems in production — runaway queues from backpressure, lost messages on disconnect, the trade-off between at-most-once and at-least-once delivery. Crank one publisher to 50 msg/s with a 1 msg/s consumer and watch the queue go red.
Teaches: Phase 5 · Systems Engineering