Rust Software Engineer

Rust Software Engineer Location: Bristol / London About Fractile 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. The Role About the Software organisation at Fractile Developer Experience sits within the Software organisation at Fractile, which is responsible for developing a full software stack for our groundbreaking AI inference systems. That's everything from ML compilers, device drivers and systems firmware, application level runtime and ecosystem integrations, ML and compute libraries, great developer tooling and a full portfolio of simulators, through to datacenter scale workload deployment solutions. At Fractile, we know that a fantastic software stack is a critical and central part of any AI inference solution and it sits at the heart of everything we're doing. About the team and role We are building a new Rust engineering team from scratch — greenfield software, with real scope to influence architecture, engineering practices, and direction from day one. The team works in a genuinely interdisciplinary environment where software engineers shape hardware decisions and vice versa. As a Rust Engineer you will build a reference implementation of a full AI inference stack in Rust, tuned to Fractile's custom hardware, write a Linux kernel driver in Rust, and develop cloud-based tooling for data centre deployments. You will research the state of the art in AI inference, bring new ideas into the codebase, and collaborate closely with hardware engineers in a true co-design loop. You will help shape the architecture, direction, and engineering culture of a new team from the ground up. About you You are energised by unfamiliar problems. You research the state of the art, form your own views, and implement them. You may be a senior engineer coming from a systems language background who has built genuine Rust proficiency through open-source or personal projects, or you may have deep experience serving AI workloads at scale. Either way, you are comfortable making sense of a problem for the first time and working autonomously in areas of ambiguity. You have a solid computer science foundation and the ability to read unfamiliar code quickly, understand it, and identify where things can be better. Key Requirements • Strong Rust skills — or senior-level experience in a systems language (C, C++) with demonstrable Rust proficiency via open source or personal projects • Experience serving AI workloads (e.g. vLLM, SGLang, or Rust equivalents), OR deep systems-level experience in areas such as low-latency data movement, paging, caching, or real-time processing • Solid computer science fundamentals and the ability to read unfamiliar code, understand it quickly, and identify problem areas • Comfort working autonomously in areas of ambiguity Nice to Have • Experience with AI inference frameworks or ML accelerator architectures • Prior startup or small-team experience • A portfolio of Rust projects you can share 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! 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.