Centralized Authentication Server: Use a centralized service (like Auth0, Okta, or Keycloak) to authenticate users once and propagate the session across the microservices through JWT tokens. Example: A user logs in through Auth0 (SSO provider) and receives a JWT token. They can
Answer: ccess multiple microservices (e.g., User Service, Order Service) by passing the token in the Authorization header.
What interviewers expect
- A clear definition tied to Microservices in Microservices projects
- Trade-offs (performance, maintainability, security, cost)
- When you would and would not use it in production
Real-world example
In a production Microservices application, teams apply this when handling user-facing features or integration boundaries. For example, you might use it during a sprint where reliability and observability matter—logging metrics, validating edge cases, and documenting the decision in an ADR so future developers understand why the approach was chosen.
How to explain in the interview
- Define the concept in one or two sentences.
- Context — where it fits in Microservices architecture.
- Example — a specific project, bug, or performance win.
- Trade-off — what you gain vs what you sacrifice.
Tip: Practice aloud on Toolliyo mock interview or the Interview Q&A section before your real interview.