Order Gateway Interview Guide
Order gateway interview guide covering order lifecycle, validation, routing, acknowledgments, cancels, rejects, idempotency, and state.
Candidates explaining order submission and exchange-facing trading systems.
Gateways manage order state
An order gateway validates requests, sends them to a venue or broker, tracks acknowledgments, cancels, rejects, and fills, and exposes a consistent state to upstream systems.
Order lifecycle is central
Discuss new, acknowledged, partially filled, filled, canceled, rejected, and unknown states. The unknown state is important because connectivity failures can make reality unclear.
Concrete example
If a cancel request times out, the system may not know whether the order is still live. A careful design reconciles with venue state rather than assuming the cancel succeeded.
Risk checks happen before submission
Price bands, size limits, duplicate order checks, and exposure limits can prevent bad orders from leaving the firm. The gateway should make failures explicit.
Common mistakes
Candidates often describe only sending orders. Interviewers may push on rejects, retries, duplicate messages, and idempotency because those details determine operational safety.
Practice the pattern
Use the LeetQuidity curriculum and calibration to turn this topic into a focused practice plan.