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System design patterns

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

3 matches

How to Build a Weighted Random Load Balancer in Python

A Python load balancer mock that distributes requests across servers based on configurable weights using a cumulative weighted random selection algorithm.

python how build

Python

import random
from collections import Counter

SERVERS = {
    "server-a": 50,
    "server-b": 30,
    "server-c": 20,
}


def weighted_random_server(servers: dict[str, int]) -> str:
    """Select a server based on its weight (higher weight = more likely)."""
    total_weight = sum(servers.values())
    rand = random.…

13 0 Open

System design patterns medium

How to Implement the Strategy Pattern in Python

This Python code demonstrates the Strategy design pattern using interchangeable sorting algorithms (bubble sort and quick sort) that can be swapped at runtime.

design-pattern strategy oop

Python

class SortingStrategy:
    def sort(self, data):
        raise NotImplementedError

class BubbleSort(SortingStrategy):
    def sort(self, data):
        result = data.copy()
        n = len(result)
        for i in range(n):
            for j in range(0, n - i - 1):
                if result[j] > result[j + 1]:
      …

13 0 Open

System design patterns easy

Round Robin Load Balancer in Python

This code simulates round robin load balancing by distributing a list of requests evenly across a list of servers.

load-balancing round-robin system-design

Python

def round_robin_servers(requests: list[str], servers: list[str]) -> dict[str, list[str]]:
    assignments = {server: [] for server in servers}
    for idx, request in enumerate(requests):
        server = servers[idx % len(servers)]
        assignments[server].append(request)
    return assignments


if __name__ == "_…

13 0 Open

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