Security Engineer - Hardware & Firmware Trust

Fractile; Tottenham; On-site; GBP 90,000 - 140,000; Full time

Benefits offered by this job

Competitive salary

Equity

Private medical

Dental and vision

Pension

25 days holiday + bank holidays

Inclusive environment

Job summary

Fractile is building the software layer for a frontier AI inference system, focusing on security across bare metal, RTOS, and Linux. You will translate threat models into concrete mechanisms, shaping the secure-by-design fabric that protects devices, racks, and fleet-wide updates.

You’ll work with architecture and hardware teams, designing and prototyping security features, and maturing them through validation in real hardware and software environments.

Qualifications

• Adversarial mindset and threat-modeling instincts for security review.
• Hands-on experience with core security primitives in software and silicon (secure boot, root of trust, cryptography, key management).
• Knowledge of secure protocol and channel design between components.
• Strong C and Rust with emphasis on memory safety and defensive coding for low-level security work.
• Experience building security mechanisms (secure-boot chain, attestation flow, key hierarchy).

Responsibilities

• Shape the security of the control chain across devices and rack controllers; define threat models and secure-by-design approaches.
• Design and help build secure boot and the root of trust on controllers: signed images, verified boot, anti-rollback, restricted privileged access.
• Secure interconnects between controllers and host with proper authentication and integrity protections.
• Design cryptographic mechanisms: key hierarchies, provisioning, device identity, remote attestation.
• Ensure safe firmware updates end-to-end across the chain: signed images, rollback protection, staged rollout.
• Harden the host Linux kernel and on-die firmware; protect running systems beyond boot.
• Collaborate with hardware and software teams to embed security across the product; conduct threat-model reviews and triage vulnerabilities.

Skills

C

Rust

Security threat modeling

Secure boot

Root of trust

Cryptography

Key management

Secure protocol design

Tools

HSM

TPM

Job description

Fractile is building the software layer for a frontier AI inference system, focusing on security across bare metal, RTOS, and Linux. You will translate threat models into concrete mechanisms, shaping the secure-by-design fabric that protects devices, racks, and fleet-wide updates.

You’ll work with architecture and hardware teams, designing and prototyping security features, and maturing them through validation in real hardware and software environments.