Article 01: What Are Microservices (Really?)

1. Objective

Understand what microservices actually are, why they exist, and when they make sense in real-world systems.

2. Key Concepts

• Monolithic architecture
• Microservices architecture
• Loose coupling
• Independent deployment
• Scalability

3. Real-World Analogy

Think of a restaurant:

• Monolith: One kitchen handles everything (orders, cooking, billing).
• Microservices: Separate teams handle orders, cooking, billing independently.

4. Monolith vs Microservices

Aspect	Monolith	Microservices
Deployment	Single unit	Independent
Scalability	Entire app	Per service
Failure Impact	Whole system	Isolated
Tech Stack	One	Polyglot

5. Hands-On: Identify Microservices

Take a simple e-commerce app and split it conceptually into:

• User Service
• Order Service
• Payment Service

6. Code Snippet (Monolith Example)

@RestController
public class OrderController {
    @PostMapping("/order")
    public String placeOrder() {
        return "Order placed";
    }
}

7. Common Mistakes

• Adopting microservices too early
• Over-splitting services
• Ignoring operational complexity

8. Interview Notes

• Microservices are about business capability, not just technology.
• They improve scalability but increase complexity.

9. Summary

Microservices are not a silver bullet. They solve specific problems of scale, deployment, and ownership.

10. What’s Next

Learn how to design microservices using domain-driven principles.