Low Latency Systems Interview Guide
Low latency systems interview guide for hot paths, measurement, networking, memory, throughput, tradeoffs, and quant developer examples.
Candidates preparing for low-latency trading systems and performance discussions.
Define latency before optimizing
Latency can mean feed-to-decision, decision-to-order, round trip, tail latency, or user-visible delay. State the measured path before proposing improvements.
Hot paths deserve simplicity
Low-latency code often reduces allocations, locks, unnecessary serialization, and work on the critical path. The right answer depends on measured bottlenecks.
Concrete example
If market data parsing dominates the path, optimizing strategy math may not help. A latency profile should identify where time is actually spent.
Tradeoffs still matter
Lower latency can increase complexity, reduce debuggability, or weaken safety if done carelessly. Discuss correctness and observability alongside speed.
Common mistakes
Candidates often suggest generic tricks before measuring. Strong answers define the path, collect percentiles, find bottlenecks, and preserve correctness.
Practice the pattern
Use the LeetQuidity curriculum and calibration to turn this topic into a focused practice plan.