Ultra-Low Latency Kernel Engineer — C++/Linux

Selby Jennings; Greater London; On-site; GBP 140,000 - 180,000; Full time

Job summary

Selby Jennings is seeking a Senior Low Latency Kernel Engineer to push the limits of Linux, networking, and hardware performance for a top-tier quantitative trading firm in London. The role focuses on kernel tuning, CPU and memory optimization, and ultra-low-latency C++ development.

You'll work with FPGA, infrastructure, and hardware teams to remove bottlenecks across the stack, using perf, eBPF, and ftrace to drive deterministic performance in trading environments.

Qualifications

• 6+ years of modern C++ experience (C++20+).
• Deep expertise in Linux internals, kernel tuning, networking, and systems programming.
• Strong understanding of CPU architecture, cache hierarchies, memory management, and performance profiling.
• Academic excellence from a top university in a quantitative field.

Responsibilities

• Optimising Linux kernels and network stacks for deterministic low-latency performance.
• Analysing CPU, cache, memory, NUMA, and scheduling behaviour.
• Developing high-performance C++20 systems used in trading and market data environments.
• Leveraging perf, eBPF, and ftrace to identify and remove bottlenecks.

Skills

C++20

Linux internals

Kernel tuning

Performance profiling

System programming

HFT exposure

Tools

perf

eBPF

ftrace

Job description

Selby Jennings is seeking a Senior Low Latency Kernel Engineer to push the limits of Linux, networking, and hardware performance for a top-tier quantitative trading firm in London. The role focuses on kernel tuning, CPU and memory optimization, and ultra-low-latency C++ development.

You'll work with FPGA, infrastructure, and hardware teams to remove bottlenecks across the stack, using perf, eBPF, and ftrace to drive deterministic performance in trading environments.