Design a Stock Trading Platform
Company: Uber
Role: Software Engineer
Category: System Design
Difficulty: medium
Interview Round: Onsite
Design a retail stock trading platform where users can buy and sell publicly traded stocks.
The system should support:
- User accounts and brokerage accounts
- Deposits and available cash balances
- Viewing real-time or near-real-time stock prices
- Placing buy and sell orders, including market and limit orders
- Canceling open orders when possible
- Receiving order status updates such as accepted, rejected, partially filled, filled, or canceled
- Viewing positions, portfolio value, and trade history
Assume this is a brokerage-style platform that routes orders to external exchanges or market makers rather than building a full high-frequency exchange from scratch.
Discuss the architecture, core services, APIs, data model, consistency guarantees, order lifecycle, failure handling, scalability, security, and compliance considerations.
Quick Answer: This question evaluates system-design competency, including distributed architecture, scalability, reliability, data modeling, transaction and order lifecycle handling, and integration with external exchanges for a retail brokerage platform, and is categorized under System Design.