Track 5 · Design Interview Problems
Design Zerodha / Groww (Stock Trading Order Matching)
NSE at 09:15 AM open. How an in-memory price-time priority matching engine processes 100,000 orders per second with microsecond latency and zero database transactions in the critical path.
Interview problem25 min read1 interactive
On this page
- Problem framing
- Questions I ask before drawing anything
- Requirements
- Estimation
- API design
- Data modeling and internal structs
- The Order Book data structure
- The Single-Threaded Core architecture
- Interactive matching simulator
- The Cancel vs Fill race
- Failure recovery: Deterministic log replay
- Edge cases and failure recovery
- Cross-questions interviewers will ask
- Interview Rubric: Mid-Level vs Senior / Staff