Alex Zajac

Alex Zajac

Software Engineer II @Amazon Prev. Machine Learning @ Ecole Polytechnique System Design, WebDev and AI enthusiast

Weekly DigestWeekly Digest
🍔🧠 Inside Apple Pay: The Secrets Behind 41 Million Daily Transactions

🍔🧠 Inside Apple Pay: The Secrets Behind 41 Million Daily Transactions

PLUS: 30 System Design Concepts 🧠, Simplifying MCP 📚, Visual Algorithms Cheat Sheet 📊

Alex Zajac
Alex Zajac
Weekly DigestWeekly Digest
🍔🧠 How AWS Lambda Serves Trillions on Requests a Month

🍔🧠 How AWS Lambda Serves Trillions on Requests a Month

PLUS: Instagram System Design 📸, How Cursor IDE Works 🖥️, Netflix's 140 Million Hours of Data Daily 📈

Alex Zajac
Alex Zajac
Weekly DigestWeekly Digest
🍔🧠 How DoorDash Replaced Elasticsearch for 50% Faster Searches

🍔🧠 How DoorDash Replaced Elasticsearch for 50% Faster Searches

PLUS: 15 Database Scaling Techniques 📊, Git Secrets for Engineers 🔑, Thinking Like a Staff Engineer 💡

Alex Zajac
Alex Zajac
Weekly DigestWeekly Digest
🍔🧠 How to Build a 2,000x Smaller Time Series Database in Rust

🍔🧠 How to Build a 2,000x Smaller Time Series Database in Rust

PLUS: SQL Interview Tips for Big Tech 💼, Stateful vs Stateless Architecture 🔄, Build Solid APIs with Next.js 🔧

Alex Zajac
Alex Zajac
Weekly DigestWeekly Digest
🍔🧠 How WorkMade Migrated 160K Lines of Javascript to Typescript in 6 Weeks

🍔🧠 How WorkMade Migrated 160K Lines of Javascript to Typescript in 6 Weeks

PLUS: How to Design Uber 🚗, WebSockets 101 🌲, Server Side Rendering Techniques ⚡

Alex Zajac
Alex Zajac
Weekly DigestWeekly Digest
🍔🧠 Bye Bye Passwords: How Grab Rebuilt Their Entire Auth System

🍔🧠 Bye Bye Passwords: How Grab Rebuilt Their Entire Auth System

PLUS: Top 10 Redis Use Cases 💾, 3 Tips for FAANG ⚡, Rust Parsing Simplified 🦀

Alex Zajac
Alex Zajac
Weekly DigestWeekly Digest
🍔🧠 RIP React; How Dagger Moved to Go + WebAssembly

🍔🧠 RIP React; How Dagger Moved to Go + WebAssembly

PLUS: Cameras in Airpods?! 🎧, Serverless 101 ⚡, Junion to Staff in 3 Years 🧓

Alex Zajac
Alex Zajac
Weekly DigestWeekly Digest
🍔🧠 How to Build a Real-Time Gaming Leaderboard That Scales

🍔🧠 How to Build a Real-Time Gaming Leaderboard That Scales

PLUS: Sonic-Fast Log Searches ⚡, LLMs for Staff Engineers 🤖, 25 Years Dev Insights 🧓

Alex Zajac
Alex Zajac
Weekly DigestWeekly Digest
🍔🧠 How YouTube Handles 2.5B Users: A System Design Breakdown

🍔🧠 How YouTube Handles 2.5B Users: A System Design Breakdown

PLUS: Chaos Engineering 101 🔥, How to Scale WebSockets ⚡, When to Use Query Builders? 🤔

Alex Zajac
Alex Zajac
Weekly DigestWeekly Digest
🍔🧠 How GitHub Handles 500 Million Code Push/Month

🍔🧠 How GitHub Handles 500 Million Code Push/Month

PLUS: 7 Lessons Building AI Apps 🤖, Double-Keyed Browser Caching ⚡, OpenAI's New Operator Agent 👀

Alex Zajac
Alex Zajac