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System design patterns

Sharding, load balancing, CAP tradeoffs, and scaling patterns — interview and production ready.

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How to Apply the Clean Architecture Dependency Rule in Python

Demonstrates the dependency rule with a Protocol repository, a use case, and a presenter wired together at a composition root.

clean-architecture dependency-inversion protocol
Python 
from dataclasses import dataclass
from typing import List, Protocol

class Repository(Protocol):
    def get_items(self) -> List[str]:
        ...

@dataclass
class InMemoryRepository:
    items: List[str]

    def get_items(self) -> List[str]:
        return self.items

class UseCase:
    """Application layer depends…
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