Senior Systems Engineer (Greenfield, Ultra High Performance) in London

Senior Systems Engineer (Greenfield, Ultra High Performance) in London

London Full-Time No working from home possible
Selby Jennings

Our client is a highly technical team building a greenfield, performance‑critical systems platform from first principles. This is a senior‑level role for engineers who have deep experience designing and optimising latency‑sensitive, high‑throughput production systems and enjoy operating close to the metal.

The environment is fast‑moving and adversarial, with a heavy emphasis on correctness, performance, and clear engineering thinking. Engineers are expected to take ownership of substantial parts of the system end‑to‑end.

What you'll be working on:

  • Designing and building ultra‑high‑performance systems where latency and throughput matter
  • Optimising software with a strong understanding of hardware interaction
  • Owning critical components across the full lifecycle: design, implementation, optimisation, and production
  • Solving novel, non‑obvious systems problems in a greenfield environment
  • Working in a setting with real ambiguity and technical autonomy

What they're looking for:

  • 5+ years' experience building and optimising high‑performance production systems
  • Strong background in systems engineering, not general application development
  • Experience with low‑latency, high‑throughput, or performance‑critical software
  • Proficiency in Rust, or strong C/C++ experience with willingness to switch
  • Sharp problem‑solving ability and comfort reasoning through complex, unstructured problems

Backgrounds that tend to fit well:

  • Engineers from top HFT, trading, or market‑making firms
  • Engineers from large‑scale infrastructure teams at top technology companies
  • PhDs or candidates with evidence of deep technical work (research, simulations, compilers, systems)
  • Competitive programmers or engineers with substantial low‑level side projects

Why this role:

  • Greenfield build with meaningful technical ownership
  • Work on genuinely hard performance‑driven systems problems
  • Small, highly technical team with high engineering standards
  • Higher upside: Base salary + guaranteed cash bonus + equity

If you're driven by deep systems work, performance optimisation, and building critical infrastructure from scratch, this is a rare opportunity to do so.

Apply Now!

Selby Jennings

Contact Details:

Selby Jennings Recruitment Team