application

## What I do - Design application architecture from requirements - Choose appropriate architectural patterns - Structure code into modules and layers - Handle dependencies and dependencies injection - Define component boundaries and responsibilities ## When to use me When building applications from scratch, refactoring existing code, or choosing architectural approaches. ## Architectural Patterns ### Layered Architecture - Presentation layer - Business logic layer - Data access layer - Separation of concerns - Pros: Simple, well-understood - Cons: Can lead to tight coupling ### Clean/Hexagonal Architecture - Domain layer (core) - Application layer (use cases) - Infrastructure layer (adapters) - Ports and adapters - Pros: Testable, flexible - Cons: More complex initial setup ### CQRS (Command Query Responsibility Segregation) - Separate read and write models - Different representations for queries vs commands - Event sourcing support - Pros: Optimized reads/writes - Cons: Complexity, eventual consistency ### Event-Driven Architecture - Event producers and consumers - Message queues/brokers - Event sourcing - Pros: Loose coupling, scalability - Cons: Complexity, debugging ### Microservices - Service decomposition - API gateways - Service mesh - Distributed data - Pros: Independent deployment, scaling - Cons: Distributed system complexity ## Design Patterns ### Creational - Factory Method - Abstract Factory - Builder - Prototype - Singleton ### Structural - Adapter - Bridge - Composite - Decorator - Facade - Flyweight - Proxy ### Behavioral - Chain of Responsibility - Command - Iterator - Mediator - Memento - Observer - State - Strategy - Template Method - Visitor ## Dependency Management - Dependency Injection - Inversion of Control - Service Locator - Constructor Injection - Property Injection - Interface-based design - Dependency graphs ## Module Design - High cohesion, low coupling - Single Responsibility Principle - Common Closure Principle - Acyclic Dependencies Principle - Stable Dependencies Principle - Stable Abstractions Principle