Tick to trade to port

Designing receive-data handling in a multi-port ultra-low-latency trading system

This question tests your ability to architect the data-ingestion layer of a tick-to-trade system operating across multiple 10 Gigabit Ethernet ports. It is commonly asked at high-frequency trading firms where microsecond-scale latency and consistent throughput matter critically. The challenge lies in handling sustained, high-rate packet streams from multiple sources without loss or bottleneck.

Strong candidates think through the constraints of kernel networking, hardware capabilities, and application-level buffering. The question rewards understanding of trade-offs: between kernel bypass techniques, NIC offload features, memory architecture, and the cost of copying versus sharing data. You should be prepared to reason about where packets are processed, how they flow through your system, and where synchronization or contention might occur.

• Kernel bypass and DPDK/XDP frameworks
• NIC hardware features (RSS, TSO, jumbo frames)
• Ring buffers and lock-free data structures
• NUMA awareness and CPU pinning
• Packet coalescing and batching strategies