Senior Systems Administrator

Systems AdministratorLeidos has a new and exciting opportunity for a Systems Administrator in our Intelligence Sector's Cyber & Analytics Business Area (CABA). Our talented team is at the forefront in Security Engineering, Computer Network Operations (CNO), Mission Software, Analytical Methods and Modeling, Signals Intelligence (SIGINT), and Cryptographic Key Management.At Leidos, we offer competitive benefits, including Paid Time Off, 11 paid Holidays, 401K with a 6% company match and immediate vesting, Flexible Schedules, Discounted Stock Purchase Plans, Technical Upskilling, Education and Training Support, Parental Paid Leave, and much more. Join us and make a difference in National Security!Program SummaryLeidos delivers advanced technical, engineering, and system administration expertise in direct support of a high-priority foreign engagement mission. This established effort leverages solutions, alongside tailored engineering approaches, to enable mission-critical capabilities within a secure, high-trust environment. The program supports a complex and evolving mission where experienced cleared professionals operate side-by-side with the customer to architect, integrate, modernize, and optimize systems that directly drive operational outcomes.The System Administrator will provide hands-on administration, maintenance, and troubleshooting support for mission-critical IT systems operating within secure and classified environments. This role is responsible for maintaining reliable and secure Linux and Windows infrastructure, supporting core enclave services, and resolving technical issues from the operating system through the application layer. The ideal candidate will bring strong Linux administration experience, a solid understanding of networking, virtualization, storage, and security, and the ability to support complex operational environments. This position requires a proactive administrator who can independently diagnose issues, maintain system compliance, and ensure infrastructure availability and performance.Key ResponsibilitiesSystem Administration & Troubleshooting: Administer, maintain, and troubleshoot Linux and Windows systems, diagnosing and resolving technical issues ranging from the operating system through the application layer.Linux Server Administration: Install, configure, patch, upgrade, secure, and maintain Linux servers, including RHEL, Rocky Linux, CentOS, or comparable enterprise Linux distributions.Core Infrastructure Services: Configure and maintain core enclave infrastructure services, including DHCP, DNS, domain services, identity management, authentication, and related network services.Virtualization & Infrastructure Support: Deploy and support virtualized and/or containerized environments while managing supporting infrastructure, including compute, storage, networking, and system resources.Network & Storage Administration: Support storage platforms, network connectivity, system interfaces, and associated infrastructure; troubleshoot performance, availability, and connectivity issues across complex environments.Security & Compliance: Maintain systems in accordance with applicable System Security Plans (SSPs) and secure administration requirements, including Secure the Enterprise (STE)/Secure the Network (STN) activities. Configure, monitor, and maintain security tools required to support DoD networks and cybersecurity requirements.Classified Environment Support: Provide day-to-day administration and technical support within classified operational environments, maintaining secure and reliable mixed Linux/Windows environments while ensuring systems remain operational, compliant, and mission ready.Required QualificationsTen (10) years of experience as a System Administrator supporting programs and contracts of similar scope, type, and complexity.Bachelor's degree in a technical discipline from an accredited college or university.Five (5) additional years of System Administration experience may be substituted for the bachelor's degree.Desired SkillsExperience administering or supporting AWS cloud environments.Experience with virtualization platforms such as KVM, Proxmox, VMware, or similar technologies.Experience with enterprise identity and authentication technologies such as FreeIPA, Centrify, LDAP, and Active Directory.Knowledge of PKI, TLS, certificates, encryption, and other cryptographic technologies.Experience with container technologies such as Docker, Podman, Kubernetes, or comparable platforms.Familiarity with automation and configuration management tools such as Ansible, Bash, Python, or PowerShell.Strong understanding of TCP/IP networking, DNS, routing, firewalls, system hardening, and secure network architecture.Ability to independently troubleshoot complex infrastructure issues, identify root causes, and implement sustainable technical solutions.If you're looking for comfort, keep scrolling. At Leidos, we outthink, outbuild, and outpace the status quo — because the mission demands it. We're not hiring followers. We're recruiting the ones who disrupt, provoke, and refuse to fail. Step 10 is ancient history. We're already at step 30 — and moving faster than anyone else dares.