Interview Q&A

Short answer: PI Gateway? Routing: The API Gateway routes incoming requests to the appropriate microservice based on the URL, method, or other attributes. It can also aggregate responses from multiple services and return a unified response. Example: Requests to /user are routed to the User Service, and /order to the Order Service. Load Balancing: The API… Gateway often……… integrates with a load balancer to distribute requests…

Explain a bit more

across multiple instances of a service, ensuring better resource utilization and failover support.

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.

Short answer: Routing: The API Gateway routes incoming requests to the appropriate microservice based on the URL, method, or other attributes.

Explain a bit more

It can also aggregate responses from multiple services and return a unified response. Example: Requests to /user are routed to the User Service, and /order to the Order Service. Load Balancing: The API Gateway often integrates with a load balancer to distribute requests across multiple instances of a service, ensuring better resource utilization and failover support. Example: Requests to a microservice like User Service can be distributed among several instances based on a round-robin or least-connections strategy. Caching: API Gateways can cache responses for repeated requests, reducing the load on backend services and improving response times for frequently accessed data. Example: Cache responses to user profiles for 1 minute to avoid querying the User Service on every request.

Real-world example (ShopNest)

ShopNest’s API Gateway routes /orders to the Order service and /payments to Payment—clients talk to one entry point.

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.

Short answer: API versioning allows clients to continue using older versions of an API while enabling the introduction of new features. Implementation:

Real-world example (ShopNest)

ShopNest’s API Gateway routes /orders to the Order service and /payments to Payment—clients talk to one entry point.

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.

Short answer: like logging, monitoring, and security?

Real-world example (ShopNest)

ShopNest’s API Gateway routes /orders to the Order service and /payments to Payment—clients talk to one entry point.

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.

Short answer: Multiple Registries: Maintain multiple service registries (e.g., Consul and Eureka) for redundancy, ensuring discovery continues if one service registry fails.

Explain a bit more

Health Checks: Implement health checks (liveness and readiness probes in Kubernetes) to monitor the status of services and avoid routing traffic to unhealthy instances. Circuit Breakers: Implement the Circuit Breaker pattern (using libraries like Hystrix or Resilience4j) to prevent cascading failures if a service is unavailable. Failover Mechanisms: Use failover strategies to route traffic to a backup service instance or an alternative registry if the primary one is down.

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.