Senior C++/Rust Systems Engineer — Greenfield Ownership

Selby Jennings; Greater London; On-site; GBP 90,000 - 150,000; Full time

Job summary

Selby Jennings is seeking a technically ambitious engineer to design, build, and optimise high-performance, latency-critical systems. You will own features from design through production in a greenfield project within a small elite team.

The role spans from low-level systems and networking to algorithmic performance, with heavy emphasis on profiling, benchmarking, and clear architectural decisions in a fast-moving environment.

Qualifications

• 3+ years' experience building high-performance production systems.
• Proficiency in C++ or Rust.
• Deep understanding of memory, concurrency, networking.
• Experience with latency-sensitive or high-throughput systems.
• Strong problem-solving and ownership in ambiguous environments.

Responsibilities

• Design and develop high-performance, low-latency systems in C++ or Rust.
• Optimise systems for throughput, latency, and scalability.
• Work across the full lifecycle: architecture, implementation, testing, and production deployment.
• Analyse and improve system performance through profiling and benchmarking.
• Solve complex, non-obvious technical problems in a fast-paced environment.
• Collaborate in a small, high-calibre team with significant ownership and impact.

Skills

C++

Rust

Low-latency design

Profiling

Problem solving

Ownership mindset

Distributed systems

Education

CS/Math/Physics degree

Job description

Selby Jennings is seeking a technically ambitious engineer to design, build, and optimise high-performance, latency-critical systems. You will own features from design through production in a greenfield project within a small elite team.

The role spans from low-level systems and networking to algorithmic performance, with heavy emphasis on profiling, benchmarking, and clear architectural decisions in a fast-moving environment.