Developer Experience Engineer

Fractile · London or Bristol · Full-time · Hybrid

About Fractile

Fractile is building silicon, systems, and software that redefine the frontier of AI — running the world's largest language models at radically higher speed and lower cost. Founded in 2022, our 100+ person team spans hardware and software, and we're growing fast.

But revolutionary hardware only matters if developers can get their models running on it quickly and predictably. That's where you come in.

The Role

We're looking for Developer Experience Engineers to design and build the tooling and workflows that companies will use to optimise their large language models on Fractile's next-generation inference hardware.

This is a role that sits at the intersection of deep systems knowledge and genuine empathy for developers. You'll shape how the outside world experiences Fractile — from a customer's first quickstart guide through to advanced performance profiling. You'll also be the voice of that external developer inside the company, turning real deployment pain into roadmap priorities.

You'll work in a tight hardware-software co-design loop alongside ML compiler, runtime, systems software, and silicon engineers — influencing APIs and abstractions before they're set in stone.

What You'll Do

• Design and build the tools customers use to run, optimise, and monitor large language models on Fractile hardware
• Build interfaces to diagnostic, profiling, and observability tools that help developers understand performance, debug issues, and optimise deployments
• Write 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 — translating real deployment pain into roadmap priorities
• Collaborate with ML compiler, runtime, systems software, and silicon teams to shape APIs and abstractions early in the design process

What We're Looking For

We care about depth of knowledge, empathy for developers, and a genuine drive to make complex things feel simple. You'll be a strong fit 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 in 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
• An instinct for reducing the number of steps, surprises, and rough edges between a user and a working result
• A Computer Science, Electronic Engineering, Maths, Physics, or related degree, and 5+ years of industry experience

Bonus Points

These aren't requirements, but they'd make you stand out:

• Experience with inference serving stacks (vLLM, SGLang, TensorRT-LLM, Triton) or ML compiler and runtime toolchains
• Experience working with GPUs, TPUs, or other ML 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
• Prior startup or small-team experience

How We Work

• Ownership and autonomy — you'll have real agency to drive your work forward
• Rapid iteration — we work directly with leadership to move from idea to product on ambitious timelines
• Full-stack collaboration — hardware, software, silicon, and modelling teams work closely together
• Hybrid working: 3 days onsite (London or Bristol), 2 days remote
• A team-first mindset — the best idea gets shipped, regardless of where it comes from

Why Fractile

• Shape how the world's developers experience next-generation AI hardware
• A collaborative culture built on curiosity, initiative, and technical depth
• 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.