Principal System Administrator (ONSITE)

The administrator will manage and troubleshoot a mixed Windows and Linux infrastructure, including core services such as DNS, DHCP, Active Directory, and server replication. They will resolve complex hardware and operating system issues, support helpdesk and audit activities, and contribute to patching, vulnerability remediation, system hardening, and compliance efforts. The role works closely with cybersecurity personnel and other technical staff in a classified, 24x7 operational environment, with occasional after-hours work and limited domestic travel. Responsibilities also include documenting advanced procedures and training others. This opportunity suits an experienced systems professional who holds an active Secret clearance, is comfortable working fully onsite, and has strong Windows administration, scripting, and security practices.