All labs
Lab 12
Event-Driven

Event-Driven System — Watch It Live

Fire an OrderPlaced event and watch it flow producer → broker → many consumers (Inventory, Email, Analytics, Fraud) reacting at once. Add or kill a consumer live, slow one to watch its backlog build, and switch a queue to a topic — the whole system breathing on one canvas.

One canvas, the whole system. Fire an OrderPlaced event (or auto-stream them) and watch it flow producer → broker → consumers. Switch topic↔queue, kill a consumer, or slow one — and see how the system responds.
0 events emitted
🛒
Order Service
producer
📡
Broker
fan-out
📦 Inventoryup
0 processedinbox 0
✉️ Emailup
0 processedinbox 0
📊 Analyticsup
0 processedinbox 0
🛡️ Fraud checkup
0 processedinbox 0
Event stream
// fire an event to begin

Try: turn on auto-stream in topic mode, then slow Fraud check — only its inbox grows. Now kill Email — orders still flow to everyone else. Switch to queue and watch events spread one-per-consumer instead.

What just happened