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. As Lead 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. Lead 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.