Understanding Load Balancer vs Reverse Proxy vs API Gateway

#aws #devops #fullstack #developer

When you’re building distributed systems—especially microservices—you’ll often hear about Load Balancers, Reverse Proxies, and API Gateways. They might seem similar at first glance, but each plays a distinct role in your architecture. Let’s break them down and see how they can work together.

Load Balancer

What it does

Distributes incoming traffic across multiple backend servers
Ensures no single server becomes a bottleneck

Key benefits

Horizontal scalability
High availability through health checks and failover
Routing based on load, IP, or latency

Popular choices

AWS Elastic Load Balancer (ELB)
HAProxy
NGINX (in load‑balancing mode)

Reverse Proxy

What it does

Sits between clients and your backend servers
Forwards incoming requests to the appropriate server

Key benefits

SSL/TLS termination at the edge
Hides internal server details
Caching and compression to speed up responses
Can perform simple load distribution

Popular choices

NGINX
Apache HTTP Server

API Gateway

What it does

Acts as a single entry point for all API calls in a microservices environment
Decouples clients from your service implementations

Key benefits

Centralized authentication, authorization, and rate limiting
Request/response transformation (e.g., protocol translation, payload shaping)
API versioning and lifecycle management
Built‑in monitoring and analytics

Popular choices

Amazon API Gateway
Kong

Bringing It All Together

A common pattern is to layer these components:

Reverse Proxy (NGINX) handles SSL termination, basic routing, and caching.
API Gateway enforces security policies, rate limits, and transforms requests.
Load Balancer (ELB or HAProxy) sits behind the gateway to distribute traffic across service instances.

This approach gives you a rock‑solid, secure, and highly scalable API stack.

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👨‍💻 Prateek Agrawal
NTWIST Inc. | Ex - Innodata Inc.

🚀 Full Stack Developer (MERN, Next.js, TS, DevOps) | Build scalable apps, optimize APIs & automate CI/CD with Docker & Kubernetes 💻