Fractile Ltd

At Fractile, we're taking a revolutionary approach to computing to run the world's largest language models at scale. Building silicon, systems and software that redefine the frontier of AI only matters if developers can actually get their models running on it quickly and predictably, which is where you come in. We're looking for Developer Experience Engineers to build the tooling and workflows that companies will use to optimise their large language models onto our next generation inference hardware. In this role, you will: Design and build the tools that customers use to run, optimise, and monitor large language models on Fractile hardware. Build the interfaces to existing diagnostic, profiling, and observability tools that let developers understand performance profiles, debug issues, and optimise their deployments. Write the documentation, quickstarts, reference examples, and tutorials that define a developer's first and lasting impression of our platform. Act as the voice of the external developer inside Fractile - turning real deployment pain into roadmap priorities. Work in a tight hardware software co design loop with ML compiler, runtime, systems software, and silicon engineers to shape APIs and abstractions before they ossify. It would be great if you have: Strong software engineering fundamentals and experience building developer facing tooling, SDKs, APIs, or platforms that other engineers depend on. Excellent Python skills, with solid experience of one or more systems languages such as Rust, C++, or Go. A good understanding of modern ML workloads and the practical challenges of deploying large language models to production. Empathy for the developer experience - you instinctively reduce the number of steps, surprises, and footguns between a user and a working result. A creative and innovative mindset, and a willingness to take ownership and drive results in a fast paced environment. A Computer Science, Electronic Engineering, Maths, Physics, or related degree and 5+ years of industry experience. You may also have: Experience with inference serving stacks (vLLM, SGLang, TensorRT-LLM, Triton) or ML compiler and runtime toolchains. Experience working with GPUs, TPUs, or other machine learning accelerators. A track record of contributing to or maintaining open source developer tools or ML ecosystem projects. Experience writing technical documentation and developer education content. Previous experience in a startup or small team environment. How we work Ownership and execution: you will have full agency to drive your work forward. Hyrid: Three days per week working on-site Rapid iteration: we all work directly with top leadership to move from idea to product 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. 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.

Fractile Ltd in London is seeking an experienced engineer to own Bazel at scale and build tooling that empowers all aspects of the company. This greenfield role involves creating extensive build pipelines, collaborating closely with different teams, and impacting the engineering organization significantly. You will need at least 5 years in software or infrastructure engineering and strong experience with Bazel and CI/CD practices. The position offers a hybrid working model, with three days on-site, and the chance to work at the forefront of ML hardware and software development.

Fractile Ltd is seeking an experienced engineer in Bristol or London to own Bazel tooling. You'll design and optimize multi-language build pipelines for innovative ML hardware and software. Join a fast-growing team with ownership and impact, building the Bazel ecosystem from scratch. This role offers a hybrid work model and the chance to collaborate with various engineering teams in a dynamic environment.

Bristol Bristol or London Hybrid: Three days on-site 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. We're looking for an engineer who wants to own Bazel at scale and build the tooling that powers every part of Fractile, from ML models to kernel drivers to hardware simulation. This is a greenfield Bazel role in a fast-growing deep-tech company building a new class of ML hardware and software from first principles. What you will work on Designing and owning Bazel rules and extensions Scaling our monorepo as we grow across Python, C++, Rust, SystemVerilog and ML workloads Creating reproducible, multi-language build pipelines Optimizing CI performance across large compute clusters Defining the developer experience for every engineer at Fractile Contributing upstream to Bazel rules we depend on Why this role is unique? No legacy - you're building the Bazel ecosystem from scratch Extreme variety - ML, compilers, kernel drivers, simulators, hardware verification High impact - your work becomes the backbone of the entire engineering organization Deep collaboration with Simulation, Runtime, and Hardware teams Real ownership - you shape how Fractile builds software What we are looking for 5+ years in software or infrastructure engineering 3+ years with build systems Strong experience with Bazel Python scripting and automation Experience with CI/CD for large-scale products Bonus: ML pipelines, GitHub Actions, multi-language build systems, containers About us Founded in 2022, team of 100+ 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.

London Bristol or London Hybrid: Three days on-site 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. We're looking for an engineer who wants to own Bazel at scale and build the tooling that powers every part of Fractile, from ML models to kernel drivers to hardware simulation. This is a greenfield Bazel role in a fast-growing deep-tech company building a new class of ML hardware and software from first principles. What you will work on Designing and owning Bazel rules and extensions Scaling our monorepo as we grow across Python, C++, Rust, SystemVerilog and ML workloads Creating reproducible, multi-language build pipelines Optimising CI performance across large compute clusters Defining the developer experience for every engineer at Fractile Contributing upstream to Bazel rules we depend on Why this role is unique? No legacy - you're building the Bazel ecosystem from scratch Extreme variety - ML, compilers, kernel drivers, simulators, hardwareverification High impact - your work becomes the backbone of the entire engineeringorganisation Deep collaboration with Simulation, Runtime, and Hardware teams Real ownership - you shape how Fractile builds software What we are looking for 5+ years in software or infrastructure engineering 3+ years with build systems Strong experience with Bazel Python scripting and automation Experience with CI/CD for large-scale products Bonus: ML pipelines, GitHub Actions, multi-language build systems, containers 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.

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. 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.

A cutting-edge technology firm in Bristol seeks a Senior System Architect to define end-to-end hardware architecture for advanced AI systems. The role involves overseeing system designs, collaborating across disciplines, and mentoring team members. Candidates should have proven experience in semiconductor technology, strong communication skills, and familiarity with FPGA prototyping. The position offers a dynamic environment focused on innovation and rapid iteration, aiming to bring groundbreaking products to market.

A technology company in Bristol is seeking a Senior System Architect to define and drive the end-to-end hardware architecture for advanced AI systems. This role involves collaborating with hardware, firmware, and software teams, ensuring robust integrations and system-level coherence. Ideal candidates will have experience in system architecture within high-performance computing and be comfortable working across multiple disciplines. The position offers a dynamic work environment and the chance to make a significant impact in a rapidly growing field.

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. 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.

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. Summary We are seeking an experienced Semiconductor Test Engineer to lead the development and deployment of manufacturing test solutions for next-generation AI accelerator devices. This role spans the full silicon lifecycle from first silicon bring-up through high-volume production, with responsibility for defining test strategy, developing ATE test content, debugging complex silicon issues, and optimizing yield, coverage, and test cost. The ideal candidate will bring deep expertise in DFT methodologies, high-speed interface testing, and advanced CMOS manufacturing, and will work closely with design, DFT, packaging, and manufacturing partners to ensure robust, scalable production of high-performance compute silicon. Key Responsibilities Develop and maintain ATE test programs for an AI accelerator chip targeting high-volume manufacturing. Implement manufacturing test content for advanced CMOS designs including high-speed logic, SRAM, DRAM, and high speed IO blocks. Develop and debug structural and functional test content such as scan/ATPG, LBIST, MBIST, JTAG, and HSIO tests. Bring up first silicon on ATE, including pattern debug, tester correlation, shmooing, and corner analysis. Support testing of high-speed interfaces such as PCIe Gen6 and multi-GHz LPDDR, including at-speed tests and margining features. Execute silicon characterization and failure analysis to identify yield limiters and defect mechanisms. Optimize test coverage, test time, and cost while maintaining manufacturing robustness. Work with DFT and design teams to improve testability and close coverage gaps. Collaborate with OSATs and external partners on test program execution and debug. Support advanced packaging test flows, including die-to-die interconnect testing and package-level thermal considerations. Contribute to documentation of test programs, debug procedures, and manufacturing release materials. Support qualification, reliability testing, and high-volume manufacturing ramp. Required Qualifications 5+ years of hands-on semiconductor test engineering experience. Strong experience developing ATE test programs (Advantest 93K, Teradyne, or equivalent). Solid understanding of DFT methodologies (scan, ATPG, MBIST, LBIST) and memory test techniques. Experience debugging silicon issues at the tester and correlating failures to design or process causes. Familiarity with advanced CMOS nodes and production test challenges. Ability to work effectively in a cross-functional engineering environment. Preferred Qualifications Experience testing AI accelerators, GPUs, networking ASICs, or other high-performance compute ICs. Experience with PCIe Gen5/Gen6, LPDDR4/5/6, or other high-speed interfaces. Exposure to advanced packaging, chiplets, or multi-die test flows. Experience improving yield, reducing test time, or optimizing cost in high-volume manufacturing. 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.

Fractile Ltd in Bristol is seeking an experienced Semiconductor Test Engineer to lead the development of manufacturing test solutions for next-generation AI accelerator devices. You will play a crucial role across the silicon lifecycle, from first silicon bring-up to high-volume production. The successful candidate will have a strong background in DFT methodologies and high-speed interface testing, collaborating with various engineering teams to ensure robust production of advanced computing silicon.