Back-End Development Microservices and Cloud Back-End Architecture 3

Question 1

What is a CDN (Content Delivery Network) and how does it benefit back-end performance?

Accepted Answer

A geographically distributed network of servers that caches and serves content from locations closer to users

Answer

A CDN caches static assets (images, scripts, API responses) on edge servers around the world, reducing latency by serving content from the nearest geographic location to each user.

Question 2

What is a health check endpoint in a back-end service?

Accepted Answer

A dedicated API endpoint that reports the service's operational status for load balancers and orchestration systems

Answer

Health check endpoints (commonly /health or /status) allow load balancers, Kubernetes, and monitoring tools to determine if a service instance is ready to receive traffic.

Question 3

What is blue-green deployment?

Accepted Answer

A release strategy maintaining two identical production environments where traffic is switched from the current (blue) to the new (green) version

Answer

Blue-green deployment runs two identical environments; after deploying to the idle (green) environment and verifying it, traffic is switched instantly from blue to green, enabling zero-downtime releases and quick rollbacks.

Question 4

What is gRPC and how does it differ from REST?

Accepted Answer

gRPC uses Protocol Buffers over HTTP/2 for high-performance binary communication; REST typically uses JSON over HTTP/1.1

Answer

gRPC uses Protocol Buffers (binary serialization) over HTTP/2, offering faster serialization, strongly-typed contracts, and bidirectional streaming — advantages over REST's text-based JSON.

Question 5

What is observability in distributed back-end systems?

Accepted Answer

The ability to understand a system's internal state from its external outputs through logs, metrics, and traces

Answer

Observability combines three pillars — logs (event records), metrics (aggregated measurements), and distributed traces (request journeys across services) — to enable debugging and understanding of complex systems.

Back-End Development Practice Test

Back-End Development Practice Test

Back-End Development Microservices and Cloud Back-End Architecture 3