Senior Linux Kernel Driver Engineer

<div class="p-rich_text_section"> <div class="layout-content"> <div class="notion-selectable notion-page-block" data-block-id="14b2905b-d614-8006-a80f-dc58ff451e32"> <h2><strong>About Fractile</strong></h2> <p>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.</p> <p>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. </p> <h3><span style="font-size: 12pt;"><strong>The Role</strong></span></h3> <p><span style="font-size: 12pt;">This role sits at the boundary between host and silicon. The kernel driver is key to keeping pace with our ultra-fast devices on cutting-edge server platforms. It’s a high-leverage layer where each win shows up as real throughput and latency gains.</span></p> <p><span style="font-size: 12pt;">You’ll be there for the pre-silicon simulations, first bring-up, first end-to-end runs, and the moments where performance jumps because of something you shipped.</span></p> <h3><span style="font-size: 12pt;"><strong>What you’ll do</strong></span></h3> <ul> <li style="font-size: 12pt;"><span style="font-size: 12pt;">Design, develop, and maintain the Linux kernel driver for Fractile’s AI accelerator</span></li> <li style="font-size: 12pt;"><span style="font-size: 12pt;">Build the performance-critical kernel-space paths that keep the host stack moving: PCIe device management, DMA, memory handling, interrupt handling, and robust recovery paths</span></li> <li style="font-size: 12pt;"><span style="font-size: 12pt;">Define and evolve the userspace interface the runtime depends on, with a focus on stability, debuggability, and performance</span></li> <li style="font-size: 12pt;"><span style="font-size: 12pt;">Work in a tight co-design loop with hardware, firmware, runtime and ML engineers: validate assumptions, iterate on behaviour, and close gaps early</span></li> <li style="font-size: 12pt;"><span style="font-size: 12pt;">Improve tooling/workflows so we move fast without breaking things</span></li> </ul> <h3><span style="font-size: 12pt;"><strong>What we’re looking for</strong></span></h3> <ul> <li style="font-size: 12pt;"><span style="font-size: 12pt;">You’ve shipped and maintained Linux kernel device drivers in production. Experience with PCIe-attached devices and custom hardware interfaces is ideal.</span></li> <li style="font-size: 12pt;"><span style="font-size: 12pt;">Strong systems and performance instincts. You can reason about computer architecture, concurrency, and where the time goes</span></li> <li style="font-size: 12pt;"><span style="font-size: 12pt;">Excellent C and/or Rust, and a pragmatic approach to building high-quality, maintainable & secure kernel code</span></li> <li style="font-size: 12pt;"><span style="font-size: 12pt;">You enjoy hard kernel and system-level problems, and you take them end-to-end until the measurements move</span></li> <li style="font-size: 12pt;"><span style="font-size: 12pt;">Computer Science, Electronic Engineering, Maths, Physics, or related degree and 3+ years of industry experience</span></li> </ul> <h3><span style="font-size: 12pt;"><strong>Nice to have</strong></span></h3> <ul> <li style="font-size: 12pt;"><span style="font-size: 12pt;">GPUs / ML accelerators / high‑throughput I/O (NICs, RDMA, storage)</span></li> <li style="font-size: 12pt;"><span style="font-size: 12pt;">Hardware bring‑up or pre‑silicon simulation experience</span></li> <li style="font-size: 12pt;"><span style="font-size: 12pt;">Performance work: profiling, tracing, benchmarking, regression tracking</span></li> </ul> <p><span style="font-size: 12pt;">If you want to build the software where every driver win unlocks huge system performance, come build it together.</span></p> <h2><strong>What We Offer</strong></h2> <ul> <li>Competitive salary: A competitive salary reflective of your experience and the specialist nature of the role.</li> <li>Equity & Ownership: meaningful equity so everyone shares in the value creation</li> <li>Benefits: Private Medical, Dental and Vision, Contributory Pension, 25 Days holiday plus bank holidays and Life/Critical Illness Insurance.</li> <li>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