🔹 LLD Series #1: Singleton Design Pattern

💡 Problem:

How do we ensure that a class has only ONE instance throughout the application?

💡 Common Use Cases:

• Logger
• Configuration Manager
• Database Connection

💡 Approach:

We restrict object creation and provide a global access point.

💡 Key Idea:

• Private constructor
• Static instance
• Public method to access it

💻 Java Example:
java public class Singleton {

private static Singleton instance;

private Singleton() {}

public static Singleton getInstance() {

if (instance == null) {

instance = new Singleton();

}

return instance;

}
}

⚠️ Insight:

This version is NOT thread-safe. In multithreaded systems, we need synchronization or double-check locking.

📌 Takeaway:

Singleton is simple but tricky in real-world scenarios.

LLD #DesignPatterns #Java #SystemDesign