What Are Design Patterns?

Design patterns are tried-and-tested solutions to common software design problems. They’re not full implementations or plug-and-play code—they’re more like templates or best practices for solving certain types of problems in a reusable, understandable way.

Think of them like recipes in cooking: they provide structure, guidance, and consistency, but you still have to bring your own ingredients and adjust for your specific “kitchen.”

Why Use Design Patterns?

In front-end development (especially with React and modern JavaScript/TypeScript), patterns help you:

• Avoid reinventing the wheel: You don’t need to create your own way to handle state changes or conditional rendering from scratch.

• Improve code readability and maintainability: A well-known pattern makes it easier for other devs to jump into your code.

• Encourage scalability and reusability: Patterns often promote modular thinking—something critical when building large UIs.

• Make architectural decisions easier: Choosing the right pattern for a problem gives your app a solid, scalable structure from the start.

Categories of Design Patterns

Design patterns are traditionally broken into three main categories (from the classic Gang of Four book):

1. Creational Patterns – These abstract or simplify the process of object creation. Examples:

   • Singleton – Ensures a class has only one instance (e.g., a global theme or config manager).
   • Factory – Creates objects without specifying exact class/type.
   • Builder – Helps construct complex objects step-by-step.

2. Structural Patterns – These focus on how classes and objects can be combined to form larger structures. Examples:

   • Adapter – Makes one interface work with another (e.g., integrating APIs).
   • Decorator – Adds behavior to an object dynamically (like higher-order components in React).
   • Facade – Provides a simplified interface to a larger body of code.

3. Behavioral Patterns – These deal with how objects interact and delegate responsibility. Examples:

   • Observer – One object notifies others of state changes (like React’s state + effect system).
   • Strategy – Lets you switch between different algorithms/behaviors at runtime.
   • Command – Encapsulates a request as an object (great for undo/redo, or dispatching events).

Bonus: Front-End Focused Patterns

Modern front-end work, especially with React, often involves UI-specific or architecture-oriented patterns such as:

• Container/Presenter (Smart/Dumb components)
• Compound Components
• Render Props
• Custom Hooks as reusable logic containers
• State machines and statecharts (like XState)