What design patterns are commonly used in TypeScript architecture?

• Singleton: Ensures a class has only one instance and provides a global point of access. Useful for managing shared resources. • Factory: Defines an interface for creating objects but allows subclasses to alter the type of objects that will be created. Good for handling complex object creation. • Observer: A way to provide a subscription mechanism to allow multiple objects to listen and react to events or state changes. Enhances decoupling.