High-Scale Distributed Systems Design

Learn how large applications stay fast and available under load:

• Horizontal scaling — adding more machines instead of bigger ones, and load-balancing traffic across them.
• Consistent hashing — distributing keys across nodes so that adding/removing a node only reshuffles a small fraction of data.
• Replication & consistency trade-offs — the CAP theorem: under a network partition, a system must choose between consistency and availability.
• Caching layers (e.g. Redis) to absorb read-heavy traffic before it reaches the database.

services:
  gateway-proxy:
    image: envoyproxy/envoy:v1.26
    ports:
      - "443:443"
    deploy:
      replicas: 5
      placement:
        constraints: [node.labels.zone == us-east-1]

Systems Programming with Rust

Rust guarantees memory safety without a garbage collector through its ownership system: every value has exactly one owner, and the compiler tracks when values move, borrow, or go out of scope. This eliminates entire classes of bugs (use-after-free, data races) at compile time.

fn main() {
    let data = String::from("build systems");
    let borrowed = &data;          // immutable borrow
    println!("{} -> {}", data, borrowed);

    let mut counter = vec![1, 2, 3];
    counter.push(4);               // mutable, single owner
    println!("{:?}", counter);
}

React Fundamentals for Production UIs

React builds interfaces from small, composable components that re-render automatically when their state changes. The useState and useEffect hooks are the two most common building blocks for state and side effects.

import { useState } from "react";

function Counter() {
  const [count, setCount] = useState(0);
  return (
    <button onClick={() => setCount(count + 1)}>
      Clicked {count} times
    </button>
  );
}

Containers & Deployment with Docker

A container packages an application with its dependencies into a single, portable image that runs identically across environments. A Dockerfile describes how to build that image layer by layer.

FROM node:20-alpine
WORKDIR /app
COPY package*.json ./
RUN npm ci --production
COPY . .
EXPOSE 3000
CMD ["node", "server.js"]