Systems Administrator - TS/SCI w/FULL SCOPE POLY with Security Clearance

Yellowfin Technology is seeking motivated System Administrators (SA1, SA2, and SA3) to support mission-critical systems within the Intelligence Community. Our System Administrators are responsible for maintaining secure, reliable, and high-performing enterprise IT environments that directly support national security missions. Whether you are an early-career administrator or an experienced enterprise technical lead, you will have the opportunity to work alongside highly skilled engineers supporting complex Windows, Linux, and virtualized environments.

Position Overview
System Administrators provide operational support for enterprise infrastructure by installing, configuring, monitoring, maintaining, and troubleshooting servers, operating systems, virtualization platforms, storage, and network-connected systems. Successful candidates will ensure system availability, optimize performance, maintain security compliance, and support mission operations in classified environments.

Higher-level System Administrators provide technical leadership, support enterprise architecture initiatives, resolve complex integration challenges, and mentor junior administrators.

Primary Responsibilities • Install, configure, administer, and maintain Windows, Linux, and UNIX operating systems. • Monitor enterprise infrastructure including servers, storage, network devices, and virtual environments. • Perform system troubleshooting, root cause analysis, and problem resolution. • Support hardware, software, operating system, and application installation and upgrades. • Perform system patching, configuration management, and security hardening. • Monitor system health, capacity, availability, and performance. • Support virtualization technologies including VMware and virtual machine security. • Maintain technical documentation, system configurations, and operational procedures. • Assist with incident response, system recovery, and disaster recovery activities. • Support infrastructure modernization and continuous process improvement. • Collaborate with engineers, cybersecurity personnel, developers, and mission stakeholders. • Communicate system status, outages, risks, and technical solutions to leadership and customers.

Required Qualifications • Bachelor's degree in Computer Science, Information Technology, Systems Engineering, or a related technical discipline. ◦ Additional System Administration experience may substitute for a degree. • Experience administering Windows, Linux, or UNIX operating systems. • Experience supporting enterprise IT infrastructure. • Strong troubleshooting and analytical skills. • Excellent written and verbal communication skills. • Active TS/SCI with Polygraph (CI or Full Scope) required.

Preferred Technical Experience
Experience with one or more of the following: • Windows Server • Linux / UNIX • Red Hat Enterprise Linux (RHEL) • VMware vSphere / ESXi • SELinux • ELK Stack • Tripwire • Container security • Virtual machine security • Active Directory • Enterprise monitoring tools • Configuration management • Performance monitoring • Capacity planning • System security and compliance Experience by Level
System Administrator I (SA1) • Experience: 5+ years • Supports daily system administration, monitoring, troubleshooting, Tier 1/2 support, system maintenance, and operational activities under senior guidance. • Builds foundational expertise in enterprise infrastructure, virtualization, and security.

System Administrator II (SA2) • Experience: 10+ years • Independently administers enterprise systems, performs advanced troubleshooting, manages operating system configurations, supports infrastructure improvements, and provides technical guidance to junior administrators. • Leads complex maintenance efforts and supports mission-critical operations.

System Administrator III (SA3) • Experience: 15+ years • Serves as a senior technical leader responsible for enterprise infrastructure, mission architecture support, complex server and application integration, and strategic technical planning. • Provides technical oversight, mentors engineering teams, and supports large-scale enterprise modernization initiatives.

Desired Skills • Windows Server Administration • Linux / UNIX Administration • VMware • Red Hat Enterprise Linux • Enterprise Infrastructure • Server Administration • System Monitoring • Capacity Planning • Performance Optimization • Root Cause Analysis • Tier 2 / Tier 3 Support • Patch Management • Configuration Management • Security Hardening • Infrastructure Automation • Enterprise Virtualization • Technical Documentation • Cross-functional Collaboration