Systems Administrator

TIAG is now hiring a Systems Administrator / Security Engineer to serve as a key technical authority driving the hands-on administration, maintenance, and security hardening across a converged Information Technology (IT) and Operational Technology (OT) environment at Port Hueneme, CA.

In this role, the Systems Admin/Engineer will take end-to-end ownership of maintaining operational continuity, visibility, and resilience for enterprise servers, workstations, virtualization platforms, OT/ICS hardware, and specialized deployable assets such as fly-away kits.

This position requires a full-time, onsite schedule (M-F) during standard business hours in support of mission-focused Navy and Department of Defense (DoD) environments. The ideal candidate brings an authoritative, proactive mindset to systems administration, vulnerability management, and defense compliance. The Systems Administrator/Engineer will need to possess deep expertise executing ACAS and Nessus vulnerability scans, implementing DISA STIGs, and supporting Risk Management Framework (RMF) execution to achieve and maintain Authority to Operate (ATO) status.

As a collaborative thought partner to project leads, Information System Security Officers (ISSOs), and client leadership, they will resolve complex technical issues, mentor junior team members, and ensure system readiness across diverse IT/OT infrastructure.

Positions Responsibilities include:

• Administer, configure, monitor, and troubleshoot enterprise Windows, Linux, and macOS systems, servers, workstations, network devices, security appliances, and virtualized platforms.

• Maintain deployable hardware packages and expeditionary capabilities, including fly-away kits, peripherals, operating systems, security controls, and readiness baselines.

• Execute and analyze independent vulnerability scans using ACAS, Nessus, and SCAP Compliance Checker, prioritizing and validating technical remediation across IT/OT systems.

• Harden operating environments, OT/ICS components, and specialized endpoints in alignment with DISA STIGs, security baselines, and patching requirements. - Support RMF and ATO processes by implementing security controls, generating control narratives, producing technical evidence, and managing data within eMASS and VRAM.

• Perform routine system hygiene, account management, endpoint maintenance, asset tracking, and log reviews to ensure continuous compliance and operational readiness.

• Develop security architecture diagrams and control-to-component traceability, while providing technical leadership and mentoring to cross-functional team members.