Senior Compiler Engineer

About OLIX

OLIXAI is growing faster than any technology in history and the explosion in demand has created a massive infrastructure gap; we can no longer build chips or power stations fast enough to keep up. The industry is still leaning on a ten-year-old hardware blueprint that has reached its limit. A new paradigm that is faster and more efficient will be the biggest economic opportunity of the next century and create the most important company of the next decade. OLIX is building this next paradigm; the Optical Tensor Processing Unit (OTPU) achieves performance and energy efficiency that is impossible to match from existing chips.

The role

We’re searching for Senior Compiler Engineers to join the team building the ML backend (compiler, run-time, and debugger) for our next-generation OPTUs that connect PyTorch, Tensorflow, JAX, and MXNet down to our low-level kernel drivers. Your mission will be to create seamless support for a broad ecosystem of large AI models, and ensure we are pushing the limits of their performance envelope by closely partnering with hardware and modelling teams to understand device trade-offs.

Responsibilities

• 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 Olix.
• Architect & Build: Design and implement our compiler, runtime, and debugger for PyTorch, TensorFlow, JAX, and MXNet on custom hardware.
• Optimise Performance: Apply advanced techniques (layout, fusion, scheduling, tiling) to eliminate bottlenecks and maximise throughput.
• Mentor & Encourage Standards: Lead code reviews, coach peers, and uphold best practices in ML backend and performance engineering for your team.
• Guide Team Direction: Stay ahead of GPU, AI accelerator, and optical computing trends; propose and prototype innovations.

Skills & Experience

• 5+ years of experience in software engineering with a focus on C/C++ programming.
• Deep expertise in ML framework internals, compilers, low-level programming, and optimisation techniques.
• Deep expertise in optimising Tensorflow, PyTorch or JAX deep learning models.
• Deep expertise with multiple toolchains like LLVM, OpenXLA/XLA, MLIR, TVM.
• Practical experience applying machine learning in high-performance computing contexts.
• Strong problem-solving skills and the ability to think critically and creatively.
• Experience in high‑pace, dynamic work environments.
• Excellent teamwork and communication skills, with the ability to collaborate effectively with cross‑functional teams.
• Bachelor's degree in computer science, electrical engineering, telecoms engineering, mathematics, or a related field.
• Personal projects are a key differentiating factor and hold more weight than other requirements.

Compensation & Benefits

• Competitive Salary: £174,000 – £234,000 annual salary commensurate with your experience, skills, and location.
• Equity & Ownership: Meaningful stock options. You’re not just joining the mission; you’re owning a piece of it.
• Proximity Bonus: We value your time. To minimise your commute and maximise your life, we offer a £24K annual Living-Local Bonus if your residence is within 20 minutes of the office.

Health & Wellbeing

• Premium Healthcare: Comprehensive BUPA medical and dental cover, including Medical History Disregarded (MHD), for complete peace of mind.
• Time Off: 25 days of annual leave, plus all UK bank holidays.

The Workspace & Tech

• Elite Hardware: M4 Macs come as standard, with M4 Pro upgrades for our engineering team. We will provide whatever you need to do your best work.
• Optimal Environment: High-spec noise-cancelling headphones and a fully ergonomic workstation designed for deep focus.
• Rapid Prototyping: Access to our high-performance 3D printing lab for work, experimentation, and personal creative projects.

Life at the Office

• Chef-prepared meals: if you need to work late.
• Caffeine on Us: We’ve got you covered with a tab at our favourite local coffee shop.

Relocation & Global Mobility

• Visa Sponsorship: We hire the best in the world. We offer full UK and international visa sponsorship.
• Seamless Relocation: Whether you’re moving across the country or across the globe, our dedicated relocation partner provides funding and concierge support to get you settled.

Due to U.S. export control regulations, candidates’ eligibility to work at Flux depends on their most recent citizenship or permanent residency status. We are generally unable to consider applicants whose most recent citizenship or permanent residence is in certain restricted countries (currently including Iran, North Korea, Syria, Cuba, Russia, Belarus, China, Hong Kong, Macau, and Venezuela). Applicants who have subsequently obtained citizenship or permanent residency in another country not subject to these restrictions may still be eligible.

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.