Layered Architecture in Software Development

Layered architecture is a design pattern that separates concerns within a software application. This separation helps in maintaining, testing, and scaling the application effectively.

• Separation of Concerns: Each layer has its own responsibilities, reducing interdependencies.
• Encapsulation: Layers interact through well-defined interfaces.
• Scalability: Easier to scale individual components without affecting the entire system.
• Maintainability: Changes in one layer minimally impact others.

Layered architecture typically consists of the following layers:

1. Presentation Layer: Handles user interface and user experience.
2. Application Layer: Contains business logic and application rules.
3. Domain Layer: Encapsulates core data and behavior of the application.
4. Data Layer: Manages data storage and retrieval.

To effectively implement layered architecture, consider the following best practices:

• Define clear interfaces between layers.
• Keep the layers loosely coupled.
• Use dependency injection to manage dependencies.
• Adhere to the Single Responsibility Principle for each layer.

Here’s a simple implementation of layered architecture in Python:

class User:
    def __init__(self, name):
        self.name = name

class UserRepository:
    def __init__(self):
        self.users = []

    def add_user(self, user):
        self.users.append(user)

    def get_users(self):
        return self.users

class UserService:
    def __init__(self, user_repository):
        self.user_repository = user_repository

    def create_user(self, name):
        user = User(name)
        self.user_repository.add_user(user)

# Presentation Layer
user_repository = UserRepository()
user_service = UserService(user_repository)

user_service.create_user("Alice")
user_service.create_user("Bob")

for user in user_repository.get_users():
    print(user.name)