Leidos is seeking a highly experienced Senior System/Network Administrator - Systems Integration to support the implementation, operation, troubleshooting, and maintenance of complex IT systems and infrastructure. You will administer Linux, UNIX, and Windows environments; build and maintain virtual and storage environments; configure network components; resolve complex technical problems; and support reliable day-to-day infrastructure operations. At this level, you will also contribute to system and mission-architecture design, understand system-administration interdependencies within Service-Oriented Architecture (SOA) environments, and resolve complex integration issues spanning server hardware, applications, and software. Mission infrastructure depends not only on the reliability of individual systems, networks, storage platforms, and virtual environments, but also on how those components interact as part of a larger architecture. As a Senior System/Network Administrator - Systems Integration, you will bring deep infrastructure experience to both operational administration and complex integration challenges, helping ensure interconnected systems and applications function effectively together. What You'll Do Systems, Network & Infrastructure Administration • Manage daily configuration and operation of IT systems. • Support implementation, troubleshooting, and maintenance of IT systems and associated infrastructure. • Monitor and support day-to-day operations across client/server, storage, network, mobile, and related devices. • Configure and manage Linux, UNIX, Windows, and other applicable operating systems. • Install and load operating-system software, troubleshoot system issues, and maintain system integrity. • Configure network components and implement operating-system enhancements to improve reliability and performance. • Build, configure, monitor, and maintain virtual environments. • Build, configure, monitor, and maintain storage environments. • Optimize system operations and resource utilization and perform system-capacity analysis and planning. Advanced Troubleshooting & User Support • Provide in-depth troubleshooting of IT systems. • Assist users in accessing and using IT systems. • Provide Tier 1 Help Desk and Tier 2 escalation support for problem identification, diagnosis, and resolution. • Support dispatch-system and hardware problems and remain engaged through resolution. • Provide detailed analysis and feedback to agency management and internal customers for escalated tickets. • Communicate system status, technical issues, and resolution progress to agency management and internal customers. Systems Integration & Mission Architecture • Support the design of systems, mission architecture, and associated hardware. • Apply working knowledge of system-administration interdependencies within Service-Oriented Architecture (SOA) environments. • Analyze and resolve complex problems involving server hardware, applications, and software integration. Required Qualifications Clearance • Active TS/SCI with Polygraph, at time of Application, to be considered for the position. Education & Experience • Fifteen (15) years of System/Network Administration experience 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/Network Administration experience may be substituted for the bachelor's degree. Original Posting: August 24, 2026 For U.S. Positions: While subject to change based on business needs, Leidos reasonably anticipates that this job requisition will remain open for at least 3 days with an anticipated close date of no earlier than 3 days after the original posting date as listed above. Pay Range: Pay Range $116,350.00 - $210,325.00 The Leidos pay range for this job level is a general guideline only and not a guarantee of compensation or salary. Additional factors considered in extending an offer include (but are not limited to) responsibilities of the job, education, experience, knowledge, skills, and abilities, as well as internal equity, alignment with market data, applicable bargaining agreement (if any), or other law.