We're searching for a Senior Performance Modelling Engineer to create and own the analytical and simulation models that steer OTPU architecture and software evolution.
Requirements
- Project Ownership: Own and deliver projects on your team's roadmap that unlock key high-impact technical and business milestones that drive the success of Flux.
- Collaboration: Work shoulder-to-shoulder with hardware, compiler and ML framework teams to ensure models reflect reality and reality meets performance goals.
- Functional Simulator: Design, build, and maintain a functional simulator of the OPTU subsystem and full pipeline.
- Performance Simulator: Design and maintain architectural & cycle-accurate models of the OPTU subsystems and pipeline. Identify throughput, latency and utilisation hot-spots; propose architectural, or scheduling fixes.
- Workload Analysis & Bottleneck Hunting: Instrument benchmarks (LLMs, diffusion, graph workloads) to collect detailed traces.
- Design-Space Exploration: Run massive parameter sweeps with your functional and to understand tradeoffs and guide the software, hardware, and optical teams. Package results into clear, quantitative analyses and design recommendations.
- Tooling & Automation: Develop Python/C++ tooling for trace parsing, statistical analysis and visualisation. Integrate models into CI so that every RTL commit gets a performance smoke test.
- 5+ years building performance or power models for CPUs, GPUs, ASICs, or accelerators.
- Strong coding ability in C++ and Python; experience with discrete-event or cycle-accurate simulators (e.g., gem5, SystemC, custom in-house).
- Solid grasp of computer-architecture fundamentals: memory systems, interconnects, queuing theory, Amdahl/Gustafson analysis.
- Familiarity with machine-learning workloads and common frameworks (PyTorch, TensorFlow, JAX).
- Comfort reading RTL or schematics and discussing micro-architectural trade-offs with hardware designers.
- Excellent data-visualisation and communication skills: able to turn millions of simulation samples into one decisive slide.
- Bachelor’s+ in EE, CS, Physics, Applied Maths or related; advanced degree preferred but not required.
- Personal or open-source projects in simulators, ML kernels, or performance analysis are a significant plus.
Benefits
- Competitive salary and stock options
- 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)
- 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
