Senior / Staff Digital Design Engineer

Company Overview

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 highly skilled and motivated Senior/Staff/Principal Digital Design Engineers with a strong focus on CMOS digital design to take end‐to‐end ownership of high‐speed, real‐time data‐processing silicon—from early algorithm modelling to verified RTL and silicon bring‐up. You will join a multidisciplinary group creating next‐generation OTPUs where digital, optical and mixed‐signal domains intersect. The ideal candidate will have a strong background in electrical engineering and semiconductor physics, along with a passion for developing reliable, high-performance digital circuits that drive breakthrough AI hardware.

Responsibilities

• Architect, design and implement high‐throughput digital pipelines (multi‐GSPS input rate, continuous streaming data paths, deep pipelining and hand‐shaking) in advanced CMOS nodes.
• Prototype and iterate rapidly in FPGA (Xilinx/AMD, Intel, or equivalent): bring‐up real‐time demos, exercise high‐speed transceivers, and feed learnings back into the ASIC.
• Model algorithms and validate concepts in MATLAB/Simulink (or equivalent), ensuring functional equivalence through to gate‐level sign‐off.
• Own RTL development (SystemVerilog / Verilog / VHDL) including synthesis, static‐timing closure, formal and constrained‐random verification.
• Analyse power, performance and area (PPA); implement innovative techniques to achieve aggressive bandwidth‐per‐watt targets.
• Collaborate with optical‐hardware, mixed‐signal and software teams to optimise data‐converter interfaces, clock‐domain crossings and firmware abstractions.
• Mentor junior engineers, lead design reviews and champion best‐practice design methodologies.

Skills & Experience

• 7+ years of hands‐on digital design for high‐performance ASICs or SoCs, including ownership of at least one product that processes a continuous real‐time data stream.
• Proven success closing timing on multi‐hundred‐MHz to multi‐GHz clock domains and integrating high‐speed IP (e.g., SerDes, HBM/DDR, PCIe, 100 GbE or similar).
• Expertise with industry‐standard EDA flows: RTL synthesis, CDC/RDC, STA, power‐intent (UPF/CPF), lint, and gate‐level simulation.
• Demonstrated FPGA prototyping skills: constraint management, transceiver tuning, and hardware debug in the lab.
• Proficiency using MATLAB/Simulink or Python/NumPy for algorithm modelling, fixed‐point analysis and test‐vector generation.
• Solid grounding in digital signal‐processing concepts, computer‐architecture fundamentals and semiconductor device physics.
• Excellent communication and cross‐functional collaboration abilities; thrives in a fast‐moving, ambiguous environment.

Nice to have

• Tape‐out experience at 22 nm or below.
• Knowledge of coherent optical links or photonic‐electronic co‐design.
• Familiarity with AI/ML workloads, systolic arrays or tensor‐processing architectures.
• Contributions to open‐source RTL, verification frameworks or FPGA boards.

Compensation & Benefits

• Competitive salary ranging from £135k+, depending on experience.
• Stock options in a rapidly growing AI company.
• Based in our new 5,000 sq. ft. office in the AI hub of Kings Cross, London.
• To foster collaboration in our high-growth environment, we require all employees to work from our London HQ and live within a 45-minute commute. We offer an extra £24,000/year incentive for those living within 20 minutes.
• Comprehensive healthcare insurance.
• 25 days PTO policy plus bank holidays.
• Private access to our in-house 3D printer.

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.