Flux Computing designs and manufactures optical processors to train and run inference on large AI models. Join us 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 motivated Senior High Speed Analog Electronics Engineer to lead the development of precision analog and mixed-signal circuitry critical to the performance of Flux’s Optical Tensor Processing Units (OTPUs). This role is ideal for an engineer with deep expertise in high-speed analog design, signal integrity, and analog/digital integration. You will work closely with cross-functional teams, including optical, digital, and FPGA engineers, to ensure high fidelity signal transmission and tight synchronisation across cutting-edge AI accelerator hardware. Responsibilities Design, simulate, and develop high-speed analog and mixed-signal circuits for use in our Optical Tensor Processing Units (OTPUs), including transimpedance amplifiers, drivers, and clock/data recovery systems. Develop and evaluate PCB designs for high-speed analog signal integrity, including layout review and parasitic modeling. Collaborate closely with optical engineers to ensure seamless integration of analog electronics with optical components. Specify and select high-speed components such as ADCs, DACs, PLLs, and precision reference sources. Define and implement strategies for signal integrity, power integrity, and noise mitigation in densely packed, high-speed environments. Conduct detailed testing and validation of analog circuits, including lab-based characterization using oscilloscopes, VNAs, and spectrum/network analyzers. Lead the development of test boards and bring-up procedures for prototype and production-level hardware. Drive root-cause analysis and debugging of performance issues across system, board, and component levels. Work with cross-functional teams including FPGA, digital logic, and system software teams to define analog/digital interfaces and operating parameters. Document designs, test procedures, and results comprehensively for internal and external review. Skills & Experience 7 years of experience in an environment of rapidly prototyping high-speed analog and mixed-signal circuit design, including amplifiers, high-speed drivers, and clocking circuits. Strong expertise in signal integrity, noise analysis, and analog simulation tools (e.g., SPICE, ADS, HFSS). Proven experience designing and validating analog front-ends for high-speed digital systems (e.g., SERDES, ADC/DAC interfaces). Extensive hands-on experience with lab equipment such as oscilloscopes, spectrum/network analyzers, and VNAs for analog testing and debugging. Familiarity with silicon validation methodologies and board-level bring-up of custom ASICs or analog ICs. Experience developing automated test frameworks for analog/mixed-signal validation (e.g., using Python, MATLAB, or LabVIEW). Strong problem-solving skills and the ability to diagnose and resolve signal integrity and analog performance issues at the component and system level. 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 including digital, optical, and software engineers. 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 do not accept unsolicited CVs from recruitment agencies, will not be liable for any fees, and prohibit unauthorised use of our company name in recruitment activities. 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.