About the job

Flux Computing designs and manufactures optical processors to train and run inference on large AI models. The company seeks a Staff Performance Modelling Engineer to develop analytical and simulation models that guide OTPU architecture and software evolution. This role involves building functional and cycle-accurate simulators of optical compute systems, conducting workload analysis, identifying performance bottlenecks, and collaborating with hardware and software teams to improve system design. The ideal candidate will have 7+ years of experience developing performance or power models for CPUs, GPUs, ASICs, or accelerators, with strong C++ and Python programming skills and expertise in simulators such as gem5 or SystemC. A deep understanding of computer architecture, queuing theory, and ML workloads is essential. Flux offers £167K–£204K annual salary, equity, full relocation support, visa sponsorship, BUPA healthcare, 25 days’ holiday plus UK bank holidays, high-spec tech, team socials, and a creative work culture in King’s Cross, London’s AI hub.