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Member of Technical Staff - Security Engineering

Fractile· Device Software
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Hybrid (London / Bristol)full-timePosted 3mo ago

About the role

Security-focused role working across hardware and software to build secure boot, root of trust, secure interconnects, and end-to-end firmware updates within Fractile’s hardware-software stack. Hybrid London/Bristol.

Responsibilities

  • Shape the security of the control chain (device, board, chassis, and rack controllers): threat models, trust boundaries, and a coherent secure-by-design approach across all platforms
  • Design and help build secure boot and the root of trust on each controller: verified/measured boot, signing and verification, anti-rollback, and locking down debug and privileged access in production
  • Secure the interconnects, between controllers and between devices and the host, with authentication, integrity, and additional protections where needed
  • Design and build the cryptographic mechanisms: key hierarchies, provisioning and storage, device identity, and remote attestation so the fleet can prove what it’s running
  • Make firmware updates safe end to end: signed images, rollback protection, staged rollout, and clean recovery, across every hop of the chain
  • Protect the running system, not just boot: harden the host Linux kernel and the on-die firmware
  • Work closely with hardware and the rest of the software team to build security into the product, running threat-model reviews, triaging vulnerabilities, and driving fixes to closure

Qualifications

  • An adversarial mindset and sharp threat-modeling instincts: trust boundaries, assets, attacks, and residual risk
  • Hands-on experience with the core security primitives in software and in silicon: secure boot, root of trust, cryptography, and key management, including how they’re implemented and where they can fail
  • Secure protocol and channel design between components
  • Strong C and Rust, and the instinct for memory safety and defensive coding that low-level security work needs
  • Experience building, not just using, security mechanisms: a secure-boot chain, key hierarchy, or attestation flow you shaped

Skills

Required:threat modelingsecure bootcryptographysecure interconnectsfirmware securityprogramming

Benefits

  • 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.
Last updated Oct 22, 2026. Interested? Apply on the company site.
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About Fractile

Radically Accelerate Frontier Model Inference

Fractile is designing AI compute systems that will enable the next generation of AI scaling: frontier model inference, 25x faster, at 1/10th the cost.

frontier model inferenceAI computecompute systemsAI scalinginference hardwareprocessor innovation
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