Top Senior System Administrator Jobs

Supports classified GPS satellite systems through system administration, integration, configuration management, security hardening, patching, vulnerability remediation, and performance monitoring. Manages Windows, Solaris, and RHEL environments, Active Directory, cybersecurity tools, network configurations, compliance documentation, and system deployments. Requires an active Secret clearance, Security+ or equivalent certification, onsite work in El Segundo, domestic travel up to 10%, and occasional after-hours on-call support.

Maintains complex, geographically distributed and air-gapped IT environments. Installs, configures, patches, hardens, troubleshoots, and optimizes Windows and Linux servers, workstations, applications, virtualization platforms, and network infrastructure. Administers Active Directory, server enclaves, security tools, PKI, vulnerability management, backups, and system documentation. Supports end users and technical teams, resolves operational issues, assists with accreditation, and communicates outage and upgrade resolutions. Requires an active Top Secret/SCI clearance with NSA full-scope polygraph and occasional travel.

Administer and maintain production CentOS/RHEL and Kubernetes environments in a high-visibility mission setting. Apply DevOps, automation, container, and configuration-management practices; support provisioning, scaling, availability, resiliency, troubleshooting, and security compliance. Collaborate with engineering teams and participate in rotating coverage to maintain daily service availability. The role requires extensive Linux administration, Kubernetes, Bash scripting, Security+, and an active DoD TS/SCI clearance with full-scope polygraph.

Install, configure, secure, operate, and maintain Linux and Windows infrastructure supporting Boeing Air Dominance programs. Responsibilities include system administration, scripting, platform integration, security solution implementation, troubleshooting, performance monitoring, service restoration, enterprise release planning, and developing Linux implementation plans. The role supports closed networks and requires an active Secret clearance, U.S. Person status, and eligibility for Special Access Programs.

Provides senior technical leadership for enterprise system administration, infrastructure operations, troubleshooting, maintenance, security, and performance. Administers Windows and Linux systems, servers, storage, networks, and cloud or hybrid environments; supports Tier 1 and Tier 2 escalations; manages patches, hardening, deployments, automation, documentation, compliance, and modernization initiatives. Mentors administrators and collaborates with engineering and development teams on DevOps, cloud, infrastructure-as-code, and application modernization.

Responsible for designing, implementing, managing and maintaining data storage systems, including performance monitoring, capacity planning, security, and disaster recovery.

Designs, implements, patches, monitors, and supports on-premises and cloud infrastructure, including VMware, Nutanix, Azure, Active Directory, networking, firewalls, storage, backups, and virtual machines. Ensures system uptime, security, compliance, disaster recovery, and infrastructure documentation. Troubleshoots issues, automates processes, supports IT initiatives, trains team members, and provides backup Help Desk coverage on a structured shift schedule.

Provides technical leadership for Windows, VMware, and Microsoft Exchange infrastructure. Administers virtual environment backups, monitors Windows servers and virtual environments, maintains system availability and security, and manages asset inventory. Leads infrastructure design, lifecycle management, performance testing, issue analysis, and high-impact IT solutions. Oversees projects from requirements through completion, including documentation and formal coordination with teams, departments, and customers.

Administer and secure IDEAS across development, staging, and production environments. Responsibilities include managing RHEL and application platforms, patching, system builds, access controls, certificates, log analysis, security remediation, change control, documentation, and Authority to Operate support. The role serves as key personnel and alternate ISSO, coordinating with database, security, DISA, and hosting teams.

Designs, deploys, and supports enterprise Windows, Linux, virtual desktop, VMware, cloud, and DevSecOps infrastructures. Develops system engineering solutions, ensures DoD compliance, manages capacity and performance, supports disaster recovery, and creates technical documentation. The role also coordinates project delivery and supports Cameo and MagicDraw deployments for an Army customer.

Provides 24/7 on-site mission support for classified IT systems, networks, and satellite ground stations. Monitors infrastructure, triages hardware and software faults, resolves mission-critical incidents, supports networking and configuration management, performs system checks, assists engineering testing, analyzes operational events, and maintains SOP/TTP documentation. The role requires real-time customer coordination, rotating Panama shifts, and active Top Secret clearance with eligibility for Top Secret/SCI.

Leads managed IT service support for external clients by overseeing ticket escalations, coaching technicians, monitoring queues, managing vendors, troubleshooting systems, reviewing project handoffs, maintaining technical documentation, and advising on client solutions. Participates in an on-call rotation and supports knowledge management, remote monitoring, and professional services automation systems.

Manages and implements Microsoft 365 services, including SharePoint, Power Platform, Azure, and OneDrive. Builds solutions, administers configurations, maintains governance and development standards, resolves platform issues, and addresses automation failures and technical debt. Tracks work through Jira or Azure DevOps, supports citizen developers, monitors platform updates, and documents policies. Provides technical guidance to junior administrators and contractors, assigns work, oversees projects, and handles escalated issues.

Administer AWS GovCloud infrastructure supporting FBI CJIS telecommunications systems. Manage AWS Connect, EC2, S3, Linux virtual machines, monitoring, patching, security controls, backups, and recovery. Automate provisioning with CloudFormation, Ansible, or Terraform; support CI/CD and DevSecOps practices; troubleshoot infrastructure issues; participate in SAFe Agile ceremonies; and provide on-call support for mission-critical systems.

Provides senior Windows systems administration and operations support across geographically distributed environments. Maintains virtual server clusters, Active Directory, DNS, Group Policy, Exchange, and SCCM; manages vulnerability patching, IAVAs, security scans, monitoring, outages, and system issues. Supports engineering requests, IT enhancements, documentation, customer communications, and on-call operations while maintaining compliance with security plans, maintenance windows, and change controls.

Supports an IC-wide mission environment and software engineering project by administering Linux systems and Kubernetes-based platforms. Responsibilities include container tooling, Bash scripting, system administration, networking, storage, authentication, security compliance, physical server administration, and classified-network support. The role may also use Python, Ansible, Salt, VMware, encryption, and key-management technologies, while requiring Security+ certification and potentially SYS3 clearance.

Administer and support enterprise server, cloud, network, identity, and Microsoft 365 infrastructure. Deploy and maintain Windows, AWS, Azure, and collaboration platforms; manage patches, backups, disaster recovery, monitoring, capacity, security controls, and automation. Provide escalation-level support within SLAs, document environments, follow change-management procedures, participate in on-call rotations, and mentor junior staff. The role is remote or hybrid in the US with occasional customer travel.

Provides advanced desktop and systems administration support for NGA College users, including troubleshooting hardware and software, installing upgrades, configuring networked systems, managing backups and recoverability, auditing workstations and servers, maintaining inventories, supporting VTC calls, training users, and leading technical projects. The role requires TS/SCI clearance, extensive systems administration experience, Security+ or CASP, ITIL certification, and flexible after-hours support.

Administer heterogeneous Windows Server and Red Hat Enterprise Linux environments, including installation, configuration, troubleshooting, DNS, DHCP, Active Directory, replication, server architecture, and hardware/OS integration. Develop technical solutions and documentation, support virtualization and storage technologies, and work onsite in a team environment. The role requires obtaining an interim Secret clearance, U.S. citizenship, and DoD 8140/8570 certification eligibility.

Designs, develops, and maintains multi-site communications network infrastructure. Manages accounts on physical and virtual machines, troubleshoots hardware, software, and networking issues, builds virtual machines, administers Windows and Linux servers, and maintains system documentation, monitoring reports, and logs. The role also performs server hardening, backups, STIG and SCAP compliance activities, routing and switching, firewall integration, and requires an active Secret clearance at Ramstein Air Base in Germany.

Administer and optimize KIPP NYC’s Salesforce platform supporting student enrollment, family engagement, marketing, and advancement. Responsibilities include configuration, user permissions, automation, integrations, reporting, dashboards, data quality, troubleshooting, documentation, training, and stakeholder support. The role partners with internal teams and vendors to improve workflows, system adoption, and operational effectiveness. It requires a hybrid schedule in Manhattan and travel to schools across New York City.

Provides technical leadership for secure Windows and RHEL physical, virtual, and classified infrastructure environments. Designs, implements, troubleshoots, monitors, and sustains enterprise systems; collaborates with engineering, networking, storage, HPC, and program teams; ensures cybersecurity and regulatory compliance; resolves support requests; maintains documentation; and mentors administrators. The role is fully onsite in a DoD closed area, requires an active Secret clearance, may involve up to 10% domestic travel, and requires after-hours support when needed.

Owns Radiant’s Microsoft 365 GCC High, Entra identity infrastructure, IAM automation, Intune endpoint management, email security, Purview information protection, SaaS platforms, and AWS workloads. The role builds automated joiner-mover-leaver processes, manages access and compliance controls, supports CMMC evidence collection, delivers platform projects, and maintains networking fundamentals. This is a fully onsite, high-ownership systems administration position requiring occasional extended hours and weekend work.

Administer and secure large-scale applications and middleware environments, including JBoss Fusion Middleware. Responsibilities include installing, configuring, maintaining, troubleshooting, deploying, testing, tuning, and securing applications across operating systems. The role requires supporting large organizations, working with multiple hardware and software solutions, and administering middleware platforms. An active Secret clearance and technical bachelor’s degree are required.

Provides advanced desktop and systems administration support for NGA College users and IT environments. Responsibilities include troubleshooting complex hardware and software issues, managing Windows, Citrix, SCCM, VDI, configurations, upgrades, backups, audits, and system performance. The role coordinates IT support for events and classrooms, trains end users, develops technical solutions, supports recoverability, leads projects, and mentors junior personnel. An active TS/SCI clearance, 8+ years of experience, relevant certifications, and a bachelor’s degree or equivalent are required.