HLD prep is optimised for larger screens
Open on a laptop or desktop (1024px+) for the diagram canvas and the section sidebar side-by-side.
Problem Understanding
Restate the problem in your own words.
Design a Stock Exchange Matching Engine
Design a stock-exchange / matching engine: orders flow in (limit + market), match against the order book, settle within microseconds, replicate state to backups, and emit market data to thousands of subscribers in real time. The hard parts are deterministic ordering (sequence number + replicas), the latency floor (kernel-bypass or FPGA at the limit), and atomic order-book updates without lock contention. Mistakes cost real money, so reproducibility from the event log is non-negotiable.
- NASDAQINET matching engine; sub-100 µs end-to-end on FPGA.
- NYSEPillar exchange; mix of electronic + DMM (designated market maker) hybrid.
- IEXFamous ‘speed bump’ design — deliberately adds 350 µs of fibre to neutralise HFT advantages.
- Binance / CoinbaseCrypto matching engines — same data structures, far simpler regulatory plumbing.
Your task: read the problem above, then write what the system is, who uses it, the rough scale, and the headline UX expectation — in your own words. Submit for AI review when you're ready.
Click any step in the sidebar to jump around — sections don't have to be done in order. Press ? any time to see all shortcuts.