Table of Contents
Quant technical interviews test systems programming, low-latency optimization, and exchange connectivity - not LeetCode. Here are questions that separate real quant engineers from general software engineers.
What A Quant Interview Should Measure
- ✦ Production systems experience
- ✦ Latency and performance reasoning
- ✦ Exchange connectivity knowledge
- ✦ Concurrency and memory model understanding
- ✦ Ability to troubleshoot real incidents
- ✦ System design trade-off analysis
Systems & Low-Latency Questions
Use TSC (rdtsc instruction). Calibrate for CPU frequency. Handle migration between cores (affinity).
Two threads writing to different variables on same cache line. Detect with perf c2c. Fix with padding (align to 64 bytes).
Exchange & Networking Questions
Standard header (BeginString, BodyLength, MsgType, SenderCompID, TargetCompID, MsgSeqNum, SendingTime), body, trailer (CheckSum).
User-space drivers, poll-mode drivers, zero-copy, eliminates system calls and context switches.
Concurrency & Lock-Free Questions
Location changes A→B→A, thread sees A and proceeds incorrectly. Solutions: double-width CAS, hazard pointers, epoch-based reclamation.
Spinlock for very short critical sections (low latency, high CPU). Mutex for longer sections (lower CPU, higher latency).
Trading System Design Questions
Price-time priority. Arrays for price levels. Intrusive linked lists for orders. Lock-free or fine-grained locking. Cache-friendly layout.
Interview Red Flags
- ✦ Only discusses academic projects
- ✦ Cannot explain latency bottlenecks
- ✦ No understanding of production monitoring
- ✦ Unable to describe real system failures
- ✦ Focuses only on algorithms and ignores infrastructure
- ✦ Cannot justify technical trade-offs
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Quant engineering requires specialized knowledge. Test for it. Offline Pixel pre-vets quant engineers on these exact skills. Raise a request, talk to candidates, fund the project, and approve payment when the work is done.
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