Senior C++ Engineer

Senior C++ Engineer – High Performance Systems Oxford (Hybrid), £90k to £95k Avanti Recruitment is working with a deep-tech company behind a high-performance reasoning engine deployed on over 60 million devices worldwide. This is core engine development for an elite engineering team working on core C++ systems, where performance, correctness, and engineering quality are absolutely critical. The Role You’ll be working on a performance-critical C++ system, tackling problems around: * Complex data processing and reasoning * Concurrency and multithreaded systems * Memory efficiency and low-level optimisation * Cross-platform behaviour (Linux, Windows, macOS) * System-level interactions where required This is hands-on, systems-level engineering. Skills required * 10-15 years of software development experience * Strong commercial experience with modern C++ (C++17 or later) * Background in systems-level or performance-critical development * Solid understanding of multithreading / concurrency * Comfortable working close to the system (memory, OS behaviour, performance) * Passion for writing high-quality, maintainable code Bonus points * Experience with low-level optimisation * High-performance backend systems * Quant / trading systems * Database or engine development * Gaming / real-time systems * Familiarity with cross-platform development What Makes This Role Different * Work on a core product used at global scale * Strong focus on engineering quality over shortcuts * Backed by a major global technology organisation, offering stability and long-term growth If you’re a C++ engineer who enjoys working on complex, high-performance systems and wants to be part of something genuinely impactful, we’d love to hear from you