Senior Systems Software Engineer

Fractile; Greater London; On-site; GBP 90,000 - 125,000; Full time

Benefits offered by this job

Equity

Private medical

Pension

25 days holiday

Job summary

Fractile is seeking an experienced embedded systems engineer to develop firmware and management software for rack controllers and BMCs. You will work on RTOS and bare-metal environments, delivering production-ready code alongside hardware and device software teams.

Ideal candidates have strong C and/or Rust, experience with embedded Linux, and a reliability-first mindset. This role is based in the UK, with a focus on secure, scalable systems that operate at rack scale.

Qualifications

• Two+ years of industry experience shipping production-critical embedded systems across bare metal, RTOS, or embedded Linux.
• Strong C and/or Rust with focus on safety, testing, debugging, and failure modes.
• Reliability-first mindset: observability, diagnosability, and recoverable designs.
• Comfort working near hardware/software boundary and collaborating with HW, drivers, and runtime teams.
• Collaborative with high ownership and clear communication.
• Degree in CS/EE/Math/Physics or related field with 3+ years of experience.

Responsibilities

• Develop firmware and services for management controllers (rack management, BMC, board/controllers) across RTOS and bare metal.
• Build systems software for board and rack management from bring-up to production deployment.
• Implement critical flows: power-on, provisioning, monitoring/telemetry, updates, recovery, and security.
• Integrate with the wider host/device stack and runtime libraries to enable end-to-end operation.
• Collaborate with hardware and device software teams to define interfaces and debug boundary issues.

Skills

Embedded systems

C

Rust

Embedded Linux

RISC-V

ML accelerators

Education

CS/EE/Math/Physics degree

Tools

OpenBMC

Zephyr RTOS

Job description

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.

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

We build the control chain that powers on, monitors, updates, and protects devices and racks across bare metal, RTOS, and embedded Linux. It's production-critical software that keeps racks stable, updates safe, and hardware secure. It's a critical layer in turning a tokens per second benchmark into a tokens per month system, turning great silicon into reliable output at rack scale. You'll be there for the first racks coming to life and rollout days where update safety matters. Your work makes the difference between a bad failure and a clean recovery path. This is the work that makes the system something operators can trust.

What You'll Do

• Develop firmware and services for management controllers at every level: rack management, BMC, and board/device controllers (RTOS and bare metal)
• Build systems software for board and rack management, from early bring-up through to production deployment
• Implement the critical flows that keep fleets healthy: power-on and provisioning, monitoring/telemetry, updates, recovery, and security
• Integrate with the wider host/device stack (drivers and runtime libraries) so the system works end-to-end
• Work closely with hardware and device software teams to define reliable interfaces, validate behaviour, and debug boundary issues

What We're Looking For

• Proven experience shipping production-critical, reliable embedded systems across two or more of: bare metal, RTOS, embedded Linux (or deep expertise in one with clear ability to ramp the others)
• Strong C and/or Rust, and excellent engineering judgement around safety, testing, debugging, and failure modes
• A reliability-first mindset: you design for observability, diagnosability, and recovery paths that are predictable and testable
• Comfortable working close to the hardware/software boundary (bootloaders/BSP/kernel-adjacent work) and collaborating tightly with HW, driver, and runtime teams
• Collaborative and high-ownership. You communicate clearly, move fast, and enjoy working through hard problems with others
• Computer Science, Electronic Engineering, Maths, Physics, or related degree and 3+ years of industry experience

Nice to have

• Embedded platform / systems firmware experience (board management, BMC-style stacks, rack controllers)
• OpenBMC experience and/or embedded Linux image build/customisation experience
• Zephyr (or similar RTOS) experience
• Security-minded, with practical instincts around secure boot, signed updates, device identity, and designing systems that fail safe and recover cleanly (direct experience in some areas is a plus)
• Kernel device work (drivers, device tree, bring-up, perf/trace)
• Hardware bring-up experience, including lab tools (logic analysers, oscilloscopes, waveform viewers)
• RISC-V familiarity
• Experience with GPUs or ML accelerators

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.

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.