It's a known question if you've been lurking the right prep forums, which I had.
Start by clarifying the scope and requirements of the crypto brokerage platform, such as supported assets, user scale, and regulatory constraints. Then, outline a high-level architecture covering key components like order management, matching engine, wallet integration, and data storage, while discussing trade-offs between consistency, latency, and scalability. Finally, dive into critical areas like data modeling for orders and transactions, and security considerations.
Pro tip: Emphasize the importance of idempotency and exactly-once processing in financial transactions to prevent duplicate orders or double-spending, and discuss how you would handle partial failures and reconciliation.
Ask questions to understand the platform's scope: expected user base, supported cryptocurrencies, order types (market, limit), regulatory compliance needs, and integration with external exchanges or liquidity providers.
Sketch the main components: API gateway, user service, order management system, matching engine (if internal), wallet service, and data stores. Discuss how they interact and the flow of an order from placement to execution.
Focus on the order management and matching engine: how to ensure low latency, high throughput, and fairness. Discuss data models for orders, trades, and balances, and how to maintain consistency across services.
Discuss trade-offs between consistency and availability (e.g., using ACID vs. BASE), and strategies for scaling (sharding, caching, async processing). Consider regulatory and security requirements like KYC/AML and encryption.
Recap the design, highlighting how it meets the requirements and handles edge cases. Mention potential future improvements or monitoring/alerting for production readiness.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.