Senior System Architect

Fractile was founded in 2022 on the bet that, eventually, the world’s most capable AI systems would be limited in their impact by the time taken to produce useful outputs. We bet everything on the logical conclusion: that the only way to truly unlock this latent value, to make speed viable at scale, was to radically re-invent the hardware that we run our frontier AI models on. Ever since, we have been building chips and systems that tackle this problem: how to efficiently generate output at thousands of tokens per second, while handling the complexity and capacity challenges of operating large models at very long contexts.

The workloads that push to the limits of the current frontier are already transformational; it is the technical and economic limits on inference speed that are constraining progress. The defining work of the 21st century will be marked by the engine of inference delivering immense and diffuse chains of intellectual inquiry, in drug discovery, in software engineering, in materials discovery, in any field where progress is driven by deep reasoning and intelligence to resolve complex problems.

Fractile is building silicon, systems and software which will redefine the frontier of AI: running the world’s most advanced models at radically higher speed and lower cost. We have an exceptional team across hardware and software capable of bringing about this change, and we are growing fast to meet demand and deliver our product at scale.

Senior System Architect, you’ll define and drive the end-to-end hardware architecture that underpins our products from chip-level interfaces and interconnects through to board design, thermal management, and system-level integration. This isn’t just about designing elegant systems on paper. You’ll work closely with digital, and verification teams to translate architecture into working silicon and reliable hardware platforms. Expect to be hands-on in early prototyping, bring-up, and system testing. You’ll be the connective tissue between hardware, firmware, and software, ensuring architectural coherence and technical excellence across all layers.

Key Responsibilities

• Define and own the system architecture roadmap, balancing performance, power, and scalability.

• Contribute to system-level design from concept through production, coordinating with chip design, mechanical, and manufacturing teams.

• Specify system interfaces, power delivery networks, interconnects, and control subsystems.

• Guide board and platform design for early bring-up and validation.

• Partner with the software and firmware leads to ensure seamless integration and coherent system-level performance.

• Evaluate emerging technologies and components to inform architectural decisions.

• Act as a technical mentor, raising the bar for design discipline and documentation across the team.

• Represent system architecture in technical reviews, partner discussions, and customer engagements.

Skills & Experience

• Proven experience as a Systems Architect, SoC Architect, or similar role in semiconductor or high-performance computing domains.

• Deep understanding of system-level design, including power, thermal, I/O, memory, and interconnect architectures.

• Strong grasp of digital design flows.

• Experience taking complex hardware systems from concept through to mass production.

• Demonstrated ability to define and manage system requirements and trade-offs.

• Comfortable working across many disciplines, hardware, firmware, and software.

• Excellent communicator who can bridge technical depth with practical execution.

 Desirable

• Background in AI acceleration, HPC, or data-centric architectures.

• Experience with FPGA prototyping and system bring-up.

• Familiarity with modern toolchains and modelling environments (SystemC, MATLAB, etc.).

• Prior start-up or scale-up experience, someone who thrives in ambiguity and fast iteration.

  How we work

  • Ownership and execution: you will have full agency to drive your work forward

  • Rapid iteration: we all work directly with top leadership to move from idea to hardware on ambitious timelines

  • Full-stack engagement: hardware, software, silicon, and modelling teams all work closely together to create a product with generational impact

  • Optimistic and pragmatic: we possess the will to win, and to do the hard work to get us there

  • Team player mentality: the mission is bigger than any of us, and we have the curiosity and technical focus to see the best idea shipped, no matter who’s it is

  About us

  • Founded in 2022, team of 80+ which is expanding rapidly

  • Modern, open offices in London and Bristol

  • Collaborative, problem-solving culture built on deep curiosity, entrepreneurial initiative and technical fluency

  Export control and security clearance

  Certain roles may involve working on technologies subject to export restrictions. Applicants may be required to undergo additional eligibility checks to ensure compliance with applicable law.

   

• Competitive salary: A competitive salary reflective of your experience and the specialist nature of the role.

• Equity & Ownership: meaningful equity so everyone shares in the value creation

• Benefits: Private Medical, Dental and Vision, Contributory Pension, 25 Days holiday plus bank holidays and Life/Critical Illness Insurance.

• Diverse & fun office: we believe the hardest problems get solved by the broadest range of minds. We are committed to Equal Employment Opportunity through attracting and retaining a diverse team and building an inclusive environment.

Fractile is seeking to increase the clock speed of global progress, one chip at a time. We’ve recently raised $220M from investors including Founders Fund and Accel and our most important work lies ahead. Join us!

Export controls

Our work involves technologies subject to UK, US and other international export control regulations. Certain roles may require additional eligibility checks to ensure compliance with applicable law. We'll be transparent about this throughout the hiring process.