Senior Systems Design C++ Engineer

Selby Jennings; City Of London; Hybrid; GBP 90,000 - 150,000; Full time

Job summary

Selby Jennings in London is seeking a Senior C++ Engineer to help build and optimise the simulation and research platforms used by researchers and portfolio managers to develop, test, and refine investment models.

This hybrid role (3 days in the office, 2 days at home) focuses on large-scale systems engineering, performance optimisation, and research infrastructure, offering significant ownership and the chance to collaborate with world‑class engineers and researchers.

Qualifications

• Strong modern C++ expertise.
• Background in systems, platform, or infrastructure engineering.
• Experience with multithreading, concurrency, and performance optimisation.
• Strong CS fundamentals and problem-solving skills.
• Ability to operate as a senior individual contributor.

Responsibilities

• Develop and enhance mission-critical C++ platforms.
• Optimise system performance, scalability, and reliability.
• Work on memory management, concurrency, and I/O optimisation.
• Collaborate with highly technical engineers and researchers.
• Take ownership of complex, long-lived platform components.

Skills

Modern C++

Systems engineering

Multithreading

CS fundamentals

Senior IC

Job description

We're working with a leading quantitative investment firm seeking a Senior C++ Engineer to help build and optimise the simulation and research platforms used by researchers and portfolio managers to develop, test, and refine investment models. This is a hybrid role based in London (3 days in/2 days home).

This is not a trading or execution role. The focus is on large-scale systems engineering, performance optimisation, and research infrastructure.

What You’ll Do

• Develop and enhance mission-critical C++ platforms
• Optimise system performance, scalability, and reliability
• Work on low-level systems challenges including memory management, concurrency, and I/O optimisation
• Collaborate with highly technical engineers and researchers
• Take ownership of complex, long-lived platform components

What They’re Looking For

• Strong modern C++ expertise
• Background in systems, platform, or infrastructure engineering
• Experience with multithreading, concurrency, and performance optimisation
• Strong CS fundamentals and problem-solving skills
• Ability to operate as a senior individual contributor

Ideal Backgrounds

The team is particularly interested in engineers from:

• Big Tech
• Infrastructure and platform engineering teams
• Distributed systems or HPC environments
• Database, storage, search, or compute platforms
• Quantitative finance and research-focused technology firms

Why Join?

• Work on business-critical research infrastructure
• Challenging performance and systems engineering problems
• Significant ownership and autonomy
• Strong engineering culture
• Collaboration with world‑class researchers and engineers