Business Metrics:?

Short answer: Transactions per minute, user sign-ups, or other KPIs relevant to business processes. Example: Using Prometheus, you can collect response time and error rate metrics for the Payment Service, visualizing them in Grafana to ensure that the service is performing well and catching failures early.

Real-world example (ShopNest)

After payment succeeds, ShopNest publishes OrderPaid. Inventory and Notification services react independently—no giant distributed transaction.

Say this in the interview

1. Define — one clear sentence (the short answer above).
2. Example — relate it to a project like ShopNest or your real work.
3. Trade-off — when you would not use it.