Salary: £42,000 - 66,000 per year Requirements: Strong Linux experience (Rocky 9 preferred) with the ability to create and implement bespoke scripts Ability to identify best practice and validate scripts from multiple sources Proven experience applying system hardening to Linux systems Advanced proficiency with Ansible, including playbook creation and offline repository management Experience implementing firewall rules and policies in air-gapped systems Event logging, monitoring, and audit configuration Technical capability across C++, Ansible, YAML, Bash, and Python SC Clearance Willingness to travel to client site near Portsmouth Responsibilities: Design, develop, and secure a fully air-gapped environment Implement hardened configurations and firewall policies Validate scripts and support C++ environments Ensure every component of the system meets rigorous security standards Contribute to creating bespoke, secure, and compliant systems Technologies: Ansible Bash Firewall Support Linux Python Security More: We are Keystone Recruitment Partners, and we are excited to work with a specialist client focused on major projects within security and the public sector. This role offers the opportunity to design and secure critical systems while working in a precision-driven environment. Our team values technical excellence and a commitment to security standards. last updated 7 week of 2026