Load Balancer vs API Gateway
A very important conceptual question for entry or mid level software engineers.
Load Balancer
Purpose:
Distributes incoming network traffic across multiple servers.
Ensures no single server is overwhelmed, improving availability and reliability.
Use Case:
Ideal for managing traffic for web applications and services.
Features:
Balances load for optimized resource utilization.
Provides redundancy and failover support.
Operates at multiple layers (Layer 4 for TCP/UDP, Layer 7 for HTTP/HTTPS).
API Gateway
Purpose:
Acts as the entry point for API requests, managing and orchestrating traffic between clients and services.
Use Case:
Essential in microservices architectures to manage communication between clients and APIs.
Features:
Offers advanced capabilities like rate limiting, authentication, authorization, caching, and monitoring.
Handles API versioning and request/response transformations.
Adds a security layer by enforcing policies and throttling requests.
Key Differences:
Primary Focus:
Load Balancer: Distributes traffic to ensure availability and optimal resource use.
API Gateway: Manages and secures API communication with added functionalities for monitoring and performance.
Layer of Operation:
Load Balancer: Operates at both Layer 4 (network) and Layer 7 (application).
API Gateway: Operates primarily at Layer 7.
Capabilities:
Load Balancer: Provides basic traffic distribution and failover.
API Gateway: Offers advanced API management features like security, routing, and monitoring.
When to Use Each:
Load Balancer:
For distributing traffic across multiple servers to ensure high availability and reliability.
Perfect for balancing web traffic and avoiding bottlenecks.
API Gateway:
For managing and securing API requests, particularly in microservices setups.
Ideal for implementing rate limiting, authentication, and request monitoring.
Understanding the distinction between these tools reflects a candidate’s grasp of modern application architecture. It’s one of the many questions I use to evaluate not just technical knowledge but the ability to articulate key concepts clearly.
What are your go-to questions to assess foundational knowledge during interviews? Let’s share and learn from each other in the comments below!