What is Monolithic Architecture?

A monolithic application is built as one single unit where:

• UI

• Business logic

• Database access
  are all tightly coupled and deployed together.

• 

📌 Example:
One WAR/JAR contains user management, payments, orders, notifications — everything.

Characteristics:

• Single codebase

• Single deployment

• Shared database

• Tight coupling

Problems:

• Difficult to scale specific features

• One bug can crash the entire app

• Slow deployments

• Hard to adopt new technologies

🔹 What is Microservices Architecture?

Microservices break an application into small, independent services, each responsible for one business capability.

📌 Example:

• User Service

• Order Service

• Payment Service

• Notification Service

Each service:

• Has its own database

• Can be deployed independently

• Communicates via REST/Kafka

🔹 Key Differences

🔹 Real-World Example

E-commerce App

Monolith:

• Checkout bug → entire app goes down

Microservices:

• Payment service failure → catalog & cart still work

🔹 When to Choose Monolith?

• Small team

• Simple application

• MVP or early-stage startup

🔹 When to Choose Microservices?

• Large system

• High traffic

• Independent scaling needed

• Multiple teams