Systems Administrator III – Windows, Linux & AWS Security Clearance

Position: Systems Administrator III – Windows, Linux & AWS with Security Clearance
NineFX is seeking a highly experienced System Administrator Level 3 to lead administration, maintenance, optimization, and troubleshooting across complex hybrid enterprise environments. This position provides senior‑level support for Windows and Linux systems, AWS cloud workloads, automation frameworks, and enterprise security tools operating within a high-security federal setting. The SA3 serves as an escalation point for Tier 1 and Tier 2 issues, performs capacity and performance analysis, supports architecture discussions, and helps ensure mission systems remain secure, available, and compliant with DoD/IC standards.

Key Responsibilities Windows & Linux System Administration

• Administer Windows Server 2019/2022, Active Directory, DNS, Certificate Authorities, and Windows 10/11 clients

• Administer and troubleshoot Linux environments (RHEL 8/9, Amazon Linux 2023) in both cloud and hybrid infrastructures

• Install, configure, maintain, and troubleshoot OS software, storage components, network interfaces, and system services

• Implement OS‑level improvements to strengthen availability, stability, performance, and security

• Support system patching, update life cycles, and configuration management compliance
AWS Cloud Administration

• Deploy, configure, and maintain AWS core services including EC2, S3, VPC, IAM, Cloud Watch, and related environments

• Administer hybrid architectures integrating AWS workloads with on‑premises systems

• Conduct cloud monitoring, log analysis, cost/utilization reviews, and resource optimization

• Support secure cloud configurations in accordance with DoD/IC cybersecurity standards Automation & Configuration Management

• Create and maintain automation using Salt Stack, Ansible, Bash, and Python

• Develop repeatable provisioning and baseline enforcement workflows

• Enhance deployment velocity and consistency through automated CM pipelines

• Maintain configuration integrity across multi‑OS, multi‑cloud environments Enterprise Security Operations

• Deploy, configure, and maintain Trellix/McAfee agents, ePO servers, Tenable Nessus agents, and Big Fix

• Identify, assess, track, and remediate security vulnerabilities across Windows, Linux, and AWS systems

• Support compliance with federal hardening requirements, agency policies, and cybersecurity frameworks

• Maintain security documentation and support audit, reporting, and verification activities Tier 1 & Tier 2 Support

• Provide initial diagnosis and support for Help Desk tickets and end‑user requests

• Serve as Tier 2 escalation for complex system, application, or hardware issues

• Deliver detailed technical analysis and updates to agency leadership on escalated incidents

• Support dispatch activities and maintain engagement through issue resolution Operations, Troubleshooting & Architecture Support

• Provide daily operational support across client/server, storage, cloud, and mobile device environments

• Diagnose and resolve complex system interactions involving hardware, OS, virtualization, networking, and cloud components

• Support system architecture discussions and assist in designing mission systems and supporting infrastructure

• Maintain awareness of system dependencies within distributed or SOA‑based environments

Required Qualifications

• Active TS/SCI with Full‑Scope Polygraph (must already be held)

• IAT Level II (Security+ CE, GSEC, CySA+, CCNA Security, or GICSP)

• 15 years of System Administration experience supporting similar scope and complexity

• Bachelor’s degree in a technical discipline
– Five additional years of System Administration experience may substitute Preferred Skills

• AWS administration (EC2, S3, VPC, IAM)

• Linux (RHEL 8/9, Amazon Linux 2023)

• Windows Server 2019/2022, Active Directory, DNS, Certificate Authorities

• Salt Stack, Ansible, Bash, Python

• Trellix/McAfee, Nessus, Big Fix, vulnerability remediation