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're searching for a Senior/Staff Analog Design Engineer to

architect, design and bring to production ultra?high?speed (> 20 GHz analog bandwidth, > 40 GS/s) CMOS ADCs and DACs

that directly interface with our optical compute fabric.


Success in this role requires mastery of low?jitter sampling circuits, broadband front ends, and calibration techniques that deliver outstanding ENOB and power efficiency. The ideal candidate will have a strong background in electrical engineering and semiconductor physics, along with a passion for developing reliable, high-performance analogue circuits that drive breakthrough AI hardware.

Responsibilities

Define converter architectures that will deliver on the target of Analog bandwidth > 20 GHz. Design critical high?speed building blocks: bootstrapped or switch?linearised T/H, low?skew clock trees (< 50 fs rms aperture jitter), broadband input buffers, thermometer and binary?weighted current cells, dynamic element matching (DEM) and background calibration loops. Model and close performance using transistor?level and behavioural co?simulation (SpectreRF / AFS RF + Verilog?A/AMS), then drive post?layout extraction, EM/IR and thermal analysis to achieve first?silicon success. Collaborate with packaging, SerDes and PLL teams to co?design I/O impedance, ESD, supply isolation and on?interposer routing so converters integrate cleanly into multi?lane fabrics. Lead silicon bring?up: on?wafer static and dynamic tests, high?speed digitiser / AWG measurements, DNL/INL, static?power and jitter transfer characterisation; oversee production test pattern generation and built?in self?test (BIST) hooks. Mentor junior engineers, conduct rigorous design and layout reviews, and publish internal app?notes to disseminate best practices for GHz?class data?converter design. Track and inject into the team the latest advances in time?interleaving calibration, background mismatch correction, supply?noise tolerant reference generation and layout techniques.

Skills & Experience

7 + years of production CMOS data?converter design, with at least two tape?outs running 20 GHz analog bandwidth. Deep knowledge of track?and?hold linearity, aperture?jitter minimisation, current?steering DAC glitch energy reduction, capacitor and device matching, and metastability?hard comparators. Proficiency with industry EDA flows: Cadence Virtuoso, SpectreRF / AFS RF, Verilog?A/AMS, EMX / HFSS for package + on?chip inductor modelling, and mixed?signal verification. Demonstrated ability to achieve < 100 fs rms aperture jitter, < 0.5 LSB DNL/INL (post?calibration), and low?ppm clock?to?data skew in silicon. Experience incorporating digital calibration engines (DSP or ?controller?driven) for offset, gain, timing and element?mismatch correction. Solid grasp of supply?noise coupling, substrate isolation, ESD, latch?up, and advanced?node layout techniques (double patterning, EUV constraints, local interconnect). Strong lab skills: high?speed AWG/BERT operation, FFT?based dynamic testing, de?embedding, and scripting (Python / MATLAB) for data reduction. Bachelor's degree in Electrical Engineering or related field (Master's / PhD preferred). Excellent communication, cross?disciplinary collaboration, and a demonstrated ability to execute quickly in innovation?driven environments.

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.