Rust Software Engineer (Mid-Level and Senior)

Rust Engineer (Mid-Level and Senior) Fractile · London or Bristol · Full-time About Fractile We're building what we believe to be the world's fastest and most energy-efficient AI inference chip from the ground up. Founded in 2022, our 70+ person team is split equally between hardware and software — and the two halves work hand in hand to extract every last drop of performance from the architecture. This is a genuinely interdisciplinary environment, where software engineers shape hardware decisions and vice versa. If you want to work somewhere your contributions have direct, visible impact, you'll fit right in. The Role We're building a new Rust engineering team from scratch — greenfield software, with real scope to influence architecture, engineering practices, and direction from day one. You'll write server-side Rust to build a reference implementation of a full AI inference stack, specifically tuned to take advantage of the hardware we're designing. That includes a Linux kernel driver in Rust, as well as the cloud-based tooling needed to run hardware housed in data centres. This is a role for engineers who are energised by unfamiliar problems — you'll research the state of the art in AI inference, form your own views, and implement them. We encourage initiative and reward intellectual curiosity. What You'll Do 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 Develop cloud-based tooling for data centre deployments Research the state of the art in AI inference and bring new ideas into the codebase Collaborate closely with hardware engineers in a true co-design loop Help shape the architecture, direction, and engineering culture of a new team What We're Looking For We're looking for thoughtful problem solvers and technical generalists with the depth to tackle genuinely hard systems challenges. You may be a strong fit if you have: 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 adjacent areas such as low-latency data movement, paging, caching, or real-time processing A solid background in computer science and the ability to read unfamiliar code, understand it quickly, and identify problem areas Comfort working autonomously in areas of ambiguity — you'll often be the person making sense of a problem for the first time If you have a portfolio of Rust projects you can share, that will strengthen your application — but it's not a prerequisite. Our Interview Process We won't subject you to algorithmic puzzle tests. Our interviews are technical and conversational — we want to understand how you think, how you approach unfamiliar code, and where your depth lies. Expect to discuss systems concepts, Rust specifics, and real engineering trade-offs. Bonus Points These aren't requirements, but they'd make you stand out: Experience with AI inference frameworks or ML accelerator architectures Prior startup or small-team experience Languages Primary: Rust. Working knowledge of C, C++, and Python also useful. Why Fractile Greenfield Rust codebase — shape it from day one Work directly alongside hardware engineers in a true co-design environment A collaborative culture built on curiosity, initiative, and technical depth Hybrid working: 3 days onsite (London or Bristol), 2 days remote Modern offices in London and Bristol — choose your base Competitive salary and equity in a fast-growing company Export Control & 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 committed to building a diverse and inclusive team. We welcome applications from people of all backgrounds and actively encourage candidates from underrepresented groups to apply. Ready to apply? Send us your CV and a brief note on what excites you about this role.