How do you manage cross-service authentication (e.g., Single Sign-On, SSO)?

Short answer: Managing cross-service authentication in a microservices environment often involves a combination of techniques:

Real-world example (ShopNest)

ShopNest splits Catalog, Cart, Order, and Payment into services so teams can deploy catalog changes without redeploying payments.

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.