Top Systems Administrator Jobs

Administer and maintain UNIX/Linux systems, networks, and software in a DoD environment. Responsibilities include backup and recovery, software installation and configuration, security and library management, hardware installation, performance tuning, resource allocation, and troubleshooting across hardware, software, and network environments. The role requires TCP/IP and network security expertise, IAT Level II designation, and an active Top Secret T5 clearance.

Assists with hospital-wide information and communications systems under the IT Director's supervision. Works with systems specialists and support technicians, provides IT assistance, handles one shift five days weekly, and participates in overtime, on-call, and callback duties. The role involves office-based work, occasional heavy lifting, ladder and overhead work, interruptions, repetitive tasks, and some travel.

Administer and support financial systems (Blackline, Oracle Cloud EPM, Prologue, Fintrac), manage users and security, assist reconciliations, forecasting, month-end close, maintain documentation, and liaise between Finance and IT.

Administer and maintain Red Hat Enterprise Linux systems and infrastructure in classified lab, development, and production environments. Responsibilities include system configuration, patching, monitoring, troubleshooting, package management, custom RPM maintenance, performance tuning, security updates, configuration management, release testing, process documentation, and system enhancements. The role collaborates with network, software, systems engineering, cybersecurity, and project management teams while independently resolving technical issues.

Administer Windows and Linux servers, VMware virtualization, Azure and AWS cloud infrastructure, storage, networking, and enterprise backup systems. Manage Active Directory, patching, monitoring, disaster recovery, security mitigation, and lifecycle upgrades. Troubleshoot escalated infrastructure issues, provide tier-three support, maintain documentation, participate in on-call rotations, and recommend improvements to system performance, capacity, availability, and scalability.

Manage and sustain Windows server and desktop environments, including Active Directory, GPOs, RBAC, imaging, patching, software deployment, and MCM applications. Maintain hardened systems for SSP and STIG compliance, troubleshoot networking and operating-system issues, create documentation, and support security requirements. The role requires collaboration with infrastructure, security, management, and customers, with occasional after-hours and weekend work.

Supports the reliability, security, and availability of site network and infrastructure systems. Designs and deploys wired and wireless networks, configures firewalls and VPNs, monitors performance, troubleshoots outages, manages hybrid AWS and Azure environments, applies patches and backups, and maintains technical documentation. The role also collaborates with centralized network and helpdesk teams, provides technical support, and may require after-hours and weekend response.

Administer and support Linux systems across classified networks at an on-site government-contracting facility. Responsibilities include installation, patching, troubleshooting, configuration management, backup and recovery, file-system administration, security logging, audit support, testing, documentation, ticket resolution, and cross-disciplinary issue isolation. The role requires adherence to information-system security procedures, collaboration with engineering and support teams, occasional after-hours work, and handling equipment up to 50 pounds.

Administer classified Linux systems across multiple networks, including installation, patching, monitoring, configuration management, backups, recovery, security auditing, and troubleshooting. Collaborate with engineering, networking, cybersecurity, and end-user teams; maintain documentation, test releases, manage system images, and support ticketing processes. The role requires onsite work, an active Secret clearance, compliance with government security standards, occasional travel, and after-hours support as needed.

Administers and secures enterprise networks, servers, Microsoft cloud infrastructure, endpoints, identity platforms, and virtualization environments. Manages firewalls, Okta, MDM, RMM, patching, vulnerability remediation, privileged access, MFA, and zero-trust controls. Supports incident response, security monitoring, risk assessments, compliance audits, backup and disaster recovery, and infrastructure health reporting. Collaborates with IT and security teams, documents procedures and changes, participates in security improvement initiatives, and supports on-call response.

Administer and maintain Red Hat Linux infrastructure, including monitoring, user management, patching, upgrades, security hardening, performance tuning, backups, storage, and troubleshooting. Develop Ansible automation for configuration management and deployments, support users and application teams, monitor system health, resolve incidents, perform root cause analysis, and document operational procedures. The role supports an Army contract and requires an active Secret clearance.

Administers Oracle Linux systems, virtual machines, shared storage, identity and DNS services, and network infrastructure across classified and unclassified environments. Responsibilities include installation, patching, monitoring, troubleshooting, vulnerability remediation, Cisco network support, scripting, documentation, and maintaining service availability. The role requires an active TS/SCI clearance with polygraph, five or more years of systems administration experience, Linux and Cisco expertise, advanced scripting skills, and active CompTIA Security+ certification.

Administer and support Linux systems across classified networks, including installation, patching, troubleshooting, configuration management, backups, file systems, security logging, and audit support. Collaborate across software, hardware, network, and cybersecurity disciplines; manage tickets, documentation, vendor issues, testing, and system recovery. The role is fully onsite in Melbourne, Florida, requires a current Top Secret clearance and Security+ certification, and may involve after-hours work and lifting equipment.

Administer and optimize geographically distributed Linux and Microsoft server environments, including air-gapped enclaves. Responsibilities include system configuration, vulnerability assessment, patching, certificate renewal, Active Directory administration, security hardening, backup and restoration, troubleshooting, documentation, and stakeholder coordination. The role requires supporting technical teams, maintaining infrastructure reliability, and providing recommendations to management in high-assurance defense environments.

Supports advanced IT issues involving infrastructure, identity and access management, applications, and cloud systems. Collaborates with Engineering, Security, Networking, and IT Support teams to resolve incidents; documents procedures and knowledge-base content; operationalizes repetitive processes; and participates in infrastructure projects, migrations, upgrades, and technology rollouts.

Leads Linux systems administration for classified government environments, overseeing multi-user systems, networks, upgrades, monitoring, configuration management, backups, security access, and disaster recovery. The role develops technical standards, supports testing and change management, maintains security documentation and A&A submissions, advises senior leadership, coordinates with vendors and IT teams, and mentors staff. Work is fully on-site in Azusa, California, requires a current Top Secret clearance, and includes occasional travel plus after-hours or weekend support.

Provides on-site network and systems administration for a U.S. Army facility. Manages Cisco networking, firewalls, VPNs, wireless infrastructure, VMware environments, Windows servers, endpoints, VoIP, and Army A365 accounts. Performs patching, troubleshooting, hardware support, and system administration while ensuring STIG, SRG, and RMF compliance. Maintains documentation, develops compliance reports, supports outages, and coordinates technical assistance cases. Requires an active DoD Secret clearance and on-site availability.

Administer and improve Salesforce and the broader go-to-market technology stack. Responsibilities include building Flow automation, maintaining integrations, managing data quality, provisioning users through Okta, troubleshooting system issues, processing Jira requests, gathering requirements, documenting configurations, and supporting light Apex or SOQL development under senior guidance.

Administer and support Windows and Linux cloud environments across multiple classification levels. Responsibilities include system hardening, patching, vulnerability remediation, infrastructure-as-code development with Ansible, IAM and Active Directory administration, troubleshooting, root-cause analysis, customer support, and maintaining accurate configuration and access records.

Hands-on senior systems administrator supporting Windows and Linux servers, virtualization, security tooling, incident response, patching, vulnerability remediation, system hardening, documentation, and compliance for government contracts. Requires mentoring, integration of new technologies, and coordination with ISSOs/ISSMs.

Support, troubleshoot, maintain, and secure the company’s network, servers, workstations, and computer systems. Responsibilities include configuring network devices, managing servers and user access, installing equipment and software, resolving hardware and software issues, implementing security protocols, supporting users, documenting resolutions, and contributing to IT improvement projects.

Plan and maintain infrastructure environments by administering VMware, Linux, Windows, Active Directory, LDAP, DNS, Azure, and related systems. Responsibilities include patching virtual machines and endpoints, automating server maintenance, supporting Kubernetes, Rancher, AWS, and Docker environments, upgrading customer demonstration systems, and delivering demo laptops and release media. The role requires hybrid work in Colorado Springs, travel up to 50%, and an active Secret clearance.

Administers and optimizes Infor Lawson ERP environments supporting HR and payroll. Responsibilities include application and middleware server management, upgrades, patching, performance monitoring, backups, disaster recovery, access controls, LDAP and SSO integration, SQL-based data management, environment synchronization, Tier 2/3 support, documentation, and coordination with DBAs, functional leads, IAM teams, and Infor support.

Perform senior systems administration for Army intelligence systems, including Windows and UNIX configuration, software installation, server and network maintenance, troubleshooting, monitoring, backups, security, and infrastructure upgrades. Provide Tier 1 and Tier 2 support, resolve hardware and software issues, manage system integrity, support migrations, communicate escalated issues, and direct personnel. The role requires daily on-site support, TS/SCI clearance, U.S. citizenship, advanced certifications, and occasional mission travel.

Manage and monitor enterprise PKI systems, administer digital certificates (issuance, renewal, revocation), troubleshoot PKI issues, maintain CAs/RAs and HSMs, enforce PKI policies and best practices, conduct audits, document configurations and workflows, and automate tasks via scripting.