Top 5 Low latency Interview Questions
Browse 5 real-world technical and behavioral interview questions about Low latency. Review scenarios, edge cases, and architectural best practices.
Design a distributed lock manager for a high-frequency trading platform where microsecond latency is critical and stale locks can result in massive financial losses.
Designing an ultra-low latency distributed lock manager, evaluating consensus algorithms, and handling clock drift in high-frequency environments.
How do you design a global skill-based matchmaking system that prevents grandmasters from stomping novices without making them wait in a 20-minute queue?
An authoritative breakdown of horizontal matchmaking services, constraint relaxation algorithms, and distributed locking for ticket-based lobbies. Use this matchmaking answer to show the decision, trade-off, and evidence rather than a memorised definition. It also connects SBMM to the point an interviewer is testing.
How would you design an order book, and what makes it hard?
An order book is price levels in price order, each holding a time-ordered queue of orders, plus an ID index so a cancel is O(1); the hard parts are that cancels dominate the flow, the feed must be gap-checked and recoverable, and replay must be deterministic and allocation-free. It also connects matching engine to the point an interviewer is testing.
How would you put mandatory pre-trade risk checks on the order path when the desk will not accept the latency?
Pre-trade risk checks must stay on the order path without adding unacceptable latency. Keep static checks in-process, maintain bounded counters for local exposure and grant budgets for global limits, with a kill switch that fails safe. It also connects market access to the point an interviewer is testing.
What cost does kernel-bypass networking actually remove, and what do you give up to get it?
Kernel bypass moves packet handling into user space so a market-data read no longer pays a syscall boundary, a kernel-to-user copy, interrupt and softirq handling, or a scheduler wakeup. You pay for it with a core burned on busy-polling, the loss of standard network tooling, and a driver-specific build. It also connects networking to the point an interviewer is testing.