Leidos is seeking an experienced Senior Infrastructure Engineer to lead a team in supporting and maintaining an IT service management tool (ServiceNow) for a large organisation. This role predominantly requires advanced expertise in Linux administration, automation, and system integration, some basic Windows experience, along with strong team leadership and mentorship skills. The ideal candidate will be responsible for ensuring system stability, security, and performance, while guiding and supporting their team in optimizing Linux environments and infrastructure. This role requires a daily in-office presence. Everything we do is built on a commitment to do the right thing for our customers, our people and our community. Our mission and our values guide the way we do business. The foundation of our Leidos culture is our Values, Beliefs and Expectations by which we select, recognise and reward employees. They create the environment that drives us toward our mission. Passionate about customer success by being determined to understand and respond to our customers’ needs as if they were our own. United as a team, we are bound together by our conviction that ethics and integrity is core to how we operate. Leidos is a global science and technology solutions leader working to solve the world’s toughest challenges in the defence, intelligence, homeland security, civil, and health markets. The company’s 33,000 employees support vital missions for government and commercial customers. Candidate must be eligible to undergo security clearance (DV). Key Responsibilities: • System Administration & Configuration Management: Manage and maintain Red Hat Enterprise Linux (RHEL) environments running application and database servers, ensuring optimal performance and stability. Manage and maintain limited Windows Servers running ITSM agents. • Troubleshooting & Root Cause Analysis: Identify, analyse, and resolve complex system issues. • Incident & Problem Management: Implement robust incident response and problem-resolution strategies. • Performance Monitoring & Optimization: Utilize to proactively enhance system performance. • Security & Compliance: Ensure adherence to industry best practices, including patch management, vulnerability assessments, and security hardening (e.g., CIS benchmarks, STIG compliance). • Automation & Scripting: Develop automation scripts using Bash, Python, or Ansible to streamline system operations and deployments. • Documentation & Knowledge Sharing: Maintain technical documentation, including system build guides, upgrade procedures, and troubleshooting manuals. • System Upgrades & Project Support: Lead system upgrades, migrations, and integration projects, ensuring seamless execution. • Logging & Monitoring Integration: Configure and manage RHEL logs for ingestion into a SIEM (Security information and event management) ; integrate Linux systems with SCOM (with assistance from the existing SCOM Infrastructure Engineer) for health monitoring. • Antivirus & Endpoint Security: Ensure AV integration and health monitoring within Linux and Windows Server environments. • Infrastructure Integration: Collaborate closely with development, security, and operations teams to optimize Linux systems within the broader IT ecosystem. • Testing & Validation Support: Oversee execution of test scripts for platform validation, supporting testers and troubleshooting potential issues. You will have: • Proven experience as a Senior Linux Engineer, System Administrator, or similar role. • Demonstrated leadership experience, with the ability to mentor and manage a technical team. • Expertise in Red Hat Enterprise Linux (RHEL) administration, troubleshooting, and performance tuning. • Experience with configuration management tools (Ansible, Puppet, or Chef). • Strong scripting ability in Bash, Python, or Perl. • Deep understanding of networking protocols (TCP/IP, DNS, DHCP, NTP, etc.). • Familiarity with IT Service Management (ITSM) tools, preferably ServiceNow. • Familiarity with Agile/Scrum methodologies. • Knowledge of ITIL/ITSM principles and best practices. • Excellent analytical and problem-solving skills. • Exceptional communication and interpersonal skills, with the ability to collaborate effectively across teams. Additional Skills: • Familiarity with security frameworks such as CIS benchmarks and ISO 27001. • Experience with log management and SIEM solutions (ArcSight, Splunk, ELK Stack). • Hands-on experience with Linux-based high availability and disaster recovery solutions. • Familiarity with virtualization technologies. • Experience with automated patch management in Linux environments. • ServiceNow environment experience is desirable. • Experience transitioning of systems to service. WHAT DO WE DO FOR YOU? At Leidos we are PASSIONATE about customer success, UNITED as a team and INSPIRED to make a difference. We offer meaningful and engaging careers, a collaborative culture, and support for your career goals, all while nurturing a healthy work-life balance. We provide an employment package that attracts, develops and retains only the best in talent. Our reward scheme includes: • Contributory Pension Scheme • Private Medical Insurance • 33 days Annual Leave (including public and privilege holidays) • Access to Flexible benefits (including life assurance, health schemes, gym memberships, annual buy and sell holidays and a cycle to work scheme) • Dynamic Working