Email service sends confirmation 👉 This avoids tight coupling and improves scalability. Why this design?

Short answer: Prevents system failure cascade Improves performance via caching Supports independent scaling of services Common mistake (what most candidates say): “We deployed API on App Service and used SQL DB” This is incomplete and signals no system design understanding.

Real-world example (ShopNest)

ShopNest on Azure typically uses App Service + SQL Database + Blob Storage + Application Insights for monitoring.

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.