Processor Architect

About Fractile

As Processor Architect, you'll define and drive the architecture of our core compute engines, ISA definitions and programming models through to memory hierarchies, and on-chip interconnects. This isn't just about hitting PPA targets on a spreadsheet; you'll work closely with logical design, physical design, and verification teams to translate architectural intent into working silicon that performs in the real world. Expect to be hands-on in performance modelling, detailed specification writing, bottleneck analysis, pre and post-silicon validation.

You'll be the driving force behind the computational heart of our products ensuring every cycle counts and every watt is well spent.

Key Responsibilities

• Define and own the compute engine architecture specifications, balancing performance, flexibility, power, area, and design complexity.
• Lead architectural exploration from early concept through to specification, coordinating with modelling, implementation, verification, and physical design teams.
• Specify execution units, memory hierarchy, instruction sets and flow — making principled trade-offs at every level.
• Help build and maintain performance models and simulators to guide architectural decisions with data.
• Partner with the system architecture and software/modelling teams to ensure the processor delivers real-world application performance, not just benchmark wins.
• Evaluate emerging techniques — compact number formats, novel compute paradigms, advanced packaging options — to inform the architectural roadmap.
• Act as a technical mentor, raising the bar for rigour in performance analysis and architectural documentation across the team.
• Represent compute engine architecture in technical reviews, partner discussions, and customer engagements.

Skills & Experience

• Proven experience as a Processor Architect, CPU/GPU Architect, or similar role in semiconductor or high-performance computing domains.
• Deep understanding of compute engine and processor architecture and design, including matrix and vector centric floating-point arithmetic and memory hierarchies.
• Strong grasp of RTL design flows and physical design constraints and how they feed back into architectural choices.
• Experience taking processor designs from early exploration through to tapeout and post-silicon performance characterisation.
• Demonstrated ability to define and manage performance and power budgets and navigate complex trade-offs.
• Comfortable working across many disciplines, including architecture, modelling, implementation, verification, and software.
• Excellent communicator who can bridge architectural depth with system-level and product-level context.

Desirable

• Background in AI acceleration, vector/matrix compute, or domain-specific processor design.
• Experience with architectural performance modelling tools and frameworks (gem5, SystemC, custom cycle-accurate simulators).
• Familiarity with compiler and toolchain interactions, understanding how software maps to hardware.
• 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 whose it is

What We Offer

• 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!