Job Description

Flux Computing designs and manufactures optical processors to train and run inference on large AI models. Join us in London to be part of a highly motivated and skilled team that thrives on delivering impact and innovation at speed.

The Role

We are seeking an experienced and driven

Senior High Speed Electronics Engineer

to play a key role in the development, validation, and optimisation of the high-speed electrical subsystems that power Flux's Optical Tensor Processing Units (OTPUs). This position requires deep expertise in high-speed digital and analog design, signal integrity, and system-level validation. You will be instrumental in ensuring performance, reliability, and scalability from prototype to production, including the validation of silicon devices and development of automated test infrastructure. Collaborating with multidisciplinary teams, you will help bridge the gap between silicon, board-level hardware, and full system integration.

Responsibilities

Design and develop high-speed electronic circuits including SERDES interfaces, clocking networks, and memory interconnects (e.g., PCIe, DDR4/5, Ethernet). Conduct comprehensive silicon validation, including bring-up of custom ASICs and validation of electrical interfaces under real-world conditions. Develop and deploy automated hardware test setups for board-level and silicon validation, integrating scripting and measurement tools (e.g., Python, LabVIEW, or similar). Lead signal integrity and power integrity analysis, including simulation and measurement (e.g., eye diagrams, S-parameters, crosstalk analysis). Collaborate with IC design and layout teams to define I/O requirements, package constraints, and test strategies during chip development. Create high-speed PCB designs and review layouts for impedance control, routing constraints, and noise mitigation. Work closely with FPGA and embedded software teams to support interface validation and debugging at the system level. Drive root cause analysis for signal failures, timing errors, and system-level integration issues using advanced lab instrumentation (oscilloscopes, logic analysers, BERTs, VNAs). Contribute to test plan development, validation coverage analysis, and reporting for product verification and manufacturing readiness. Document technical designs, validation results, and bring-up procedures for internal stakeholders and product teams.

Skills & Experience

7+ years of experience in high-speed digital electronics design, including interfaces such as PCIe, DDR4/5, Ethernet, and SERDES. Strong understanding of signal integrity (SI) and power integrity (PI) principles, including simulation and analysis using tools like HyperLynx, ADS, or Sigrity. Proven experience with silicon bring-up and validation, including hands-on work with custom ASICs, FPGAs, or SoCs. Proficiency in developing automated test environments for hardware validation using scripting languages (e.g., Python, MATLAB) and lab tools integration. Experience with PCB design and layout for high-speed digital systems, including impedance control, differential pair routing, and minimising crosstalk. Deep understanding of embedded system architectures. Extensive experience in synchronising complex hardware components and optimising real-time system performance. Strong problem-solving skills and the ability to debug hardware-software interactions effectively. Bachelor's degree in Electrical Engineering, Electronics Engineering, or a related field; Master's or PhD preferred. Ability to thrive in a fast-paced, dynamic environment and collaborate effectively with multidisciplinary teams.

Compensation & Benefits

Competitive salary and stock options, you're not just part of the journey, you will own a piece of it. Work from our HQ in King's Cross, right in the middle of London's buzzing AI scene. Live within 45 minutes of the office? Perfect. Live within 20 minutes? We'll add an extra

24,000 a year

to your salary. We offer visa sponsorship and full relocation support (UK and abroad), through a dedicated third-party provider who are on hand to make your move to London as seamless as possible. Full BUPA healthcare and dental cover, medical history disregarded. High-spec tech for everyone - M4 Macs as standard, M4 Pros for Engineers. Sony noise-cancelling headphones and ergonomic setups to keep you comfortable and focused. Personal company card to spend on tools that help you do your job - like ChatGPT Pro or anything else that boosts your workflow. Healthy, chef-cooked dinners in the office every night, with something for every diet and tastebud. Monthly off-site team socials. 25 days of paid holiday, plus all the UK bank holidays. Access to our in-house 3D printer for personal or work projects. Cycle2work scheme. Need a caffeine fix? We've got you covered with a tab at our favourite local coffee shop. We offer a pension plan and salary sacrifice options.

We're building fast and that includes our benefits. More exciting additions are coming soon for the Flux crew.

If you are passionate about pushing the boundaries of what's possible in AI and thrive in a high-energy, fast-paced environment, we want to hear from you. Apply now to join Flux and be a key player in shaping the future of computing.