About the job

The Senior Software Engineer – Wireless PHY (Senior & Principal) role at Yoh, A Day & Zimmermann Company in Southampton, UK, is a full-time hybrid position (2–3 days/week onsite) offering a salary of £70,000–£100,000 per year, up to 20% bonus, equity, PMI, healthcare, pension, and visa sponsorship with relocation support. This technical role focuses on building and optimising real-time software in the physical layer of advanced wireless systems, where latency, throughput, and correctness are critical. Key responsibilities include developing high-performance C/C++ code on x86 or ARM architectures, real-time PHY signal-processing implementations, optimising hot code paths using SIMD/vectorisation, designing high-performance APIs for hardware-accelerated paths (Linux, PCIe, DPDK), and collaborating with DSP, FPGA, and systems teams. The position is ideal for engineers with prior experience in wireless Layer-1/PHY development, including OFDM/MIMO algorithms, channel estimation/equalisation, LDPC/Polar/Turbo coding, ORAN Split 7.2, FAPI/LLS, real-time DSP implementations, or low-latency C/C++ in hardware-adjacent systems. Senior roles focus on delivery and optimisation, while Principal roles include technical leadership and architectural responsibility. Yoh is a staffing and recruiting company with 1,001–5,000 employees, headquartered in Philadelphia, PA, operating across North America and the UK, specialising in IT, Fintech, Cloud Computing & Migration, Cybersecurity, Product Engineering, Healthcare, Life Sciences, and Media & Entertainment. The company supports diverse talent and specialised resource needs, providing career growth opportunities and exposure to cutting-edge technology projects.