- Published on
Design Patterns Learning Order
Here's a recommended learning order for design patterns that builds understanding progressively — from the most foundational to the more advanced — following the Gang of Four (GoF) classification while mixing in some practical priority for software engineers.
🔥 1. Foundational / Frequently Used Patterns
Start with patterns you'll see and use often. These build intuition about design principles like encapsulation, decoupling, and composition over inheritance.
| Pattern | Category | Why Learn It Early? |
|---|---|---|
| Singleton | Creational | Very common (but overused), controls object creation |
| Factory Method | Creational | Teaches interface-based design and object creation flexibility |
| Observer | Behavioral | Event-driven systems, core to UI, MVC, pub-sub models |
| Strategy | Behavioral | Great for replacing conditional logic and making algorithms interchangeable |
| Decorator | Structural | Introduces dynamic behavior extension (widely used in Python and Java) |
💻 2. Intermediate / Structural Patterns
These help you understand composition, abstraction, and relationships between objects.
| Pattern | Category | Why Next? |
|---|---|---|
| Adapter | Structural | Core to integrating incompatible interfaces (real-world use: wrapping APIs) |
| Composite | Structural | Useful for tree structures (UI hierarchies, file systems) |
| Facade | Structural | Teaches API simplification, subsystem management |
| Command | Behavioral | Core in undo/redo systems, task queues, UI action encapsulation |
| Template Method | Behavioral | Helps understand the "define skeleton / defer detail" principle |
🚀 3. Advanced / Architectural Impact
Once comfortable, these patterns expand your thinking toward scalable, maintainable designs.
| Pattern | Category | Where It Shines |
|---|---|---|
| Prototype | Creational | Fast cloning, object generation without new keyword |
| Builder | Creational | Complex object creation (good for fluent APIs) |
| State | Behavioral | Replace state machine conditionals cleanly |
| Mediator | Behavioral | Centralizes communication, reduces coupling |
| Chain of Responsibility | Behavioral | Request handling pipelines, middlewares |
| Flyweight | Structural | Memory optimization with shared instances |
| Visitor | Behavioral | Extend operations on complex object structures (ASTs, compilers) |
🧠 4. Optional / Niche Patterns (Good for completeness)
These are less common in everyday work but important for a complete picture.
| Pattern | Category | Note |
|---|---|---|
| Memento | Behavioral | Undo/rollback systems |
| Interpreter | Behavioral | Mini language parsers, DSLs |
| Bridge | Structural | Separates abstraction from implementation (great in large systems) |
| Proxy | Structural | Access control, lazy loading, remote access |
✅ Bonus: Learn by Use Case / Project
Rather than memorizing, implement each pattern with a small project or code snippet:
- Observer: Chat app / event system
- Strategy: Payment method selector
- Factory: Shape or vehicle creation
- Decorator: File I/O enhancements or logging
- Command: Text editor actions / undo-redo
📚 Suggested Order (Summary)
- Singleton, Factory Method, Observer, Strategy, Decorator
- Adapter, Composite, Facade, Command, Template Method
- Prototype, Builder, State, Mediator, Chain of Responsibility, Flyweight, Visitor
- Memento, Interpreter, Bridge, Proxy
Would you like: ✅ Code examples per pattern? ✅ A study roadmap table? ✅ Book / video recommendations? ✅ Python-specific examples?
Let me know how deep you want to go!