Pattern series
Pub/Sub Fan-out
6 System Design questions share this exact tag. Use the closely related series below for a fuller drill.
- 01Preview
Chat Service
Design the backend infrastructure behind a chat product — stateful connection servers, message storage, and group fan-out — for hundreds of millions o...
Discord - 02Free guide
Facebook Messenger
Design Facebook Messenger — a real-time chat system delivering messages with low latency, ordering guarantees, and multi-device sync at massive scale.
Meta - 03Preview
Google Doc
Design Google Docs’ real-time collaborative editing — multiple users typing in the same document simultaneously and seeing each other’s edits converge...
Google - 04Preview
Robinhood (Stock Trading)
Design a retail stock trading platform like Robinhood that lets millions of users place buy/sell orders, tracks cash and positions with regulatory-gra...
Robinhood - 05Preview
Stock Exchange
Design the core trading system of a stock exchange: accept orders into a central limit order book, match at price-time priority, and when your own boo...
Practice bank - 06Preview
Live Comments
Design a live comments system that fans out comments from one live event to millions of concurrent viewers in real time.
Meta