Senior Systems Engineer with Security Clearance

Position Overview We are seeking a highly skilled Senior Systems Engineer to support the Defense Information Systems Agency Citadel mission. The ideal candidate will provide advanced engineering, integration, administration, and operational support for enterprise infrastructure and mission-critical systems in a secure DoD environment. This role requires a proactive engineer with deep experience in systems architecture, virtualization, automation, cybersecurity compliance, and enterprise operations. The selected candidate will work closely with government stakeholders, cybersecurity teams, network engineers, and mission partners to ensure high availability, performance, and security across the environment.

Key Responsibilities Design, implement, maintain, and optimize enterprise systems infrastructure supporting DISA Citadel operations
Engineer and administer Linux server environments in classified (IL6) and unclassified (IL5) networks
Support virtualization platforms including VMware, Hyper-V, or cloud-based environments
Develop and maintain system documentation, architecture diagrams, SOPs, and operational procedures
Perform systems monitoring, troubleshooting, performance tuning, and root-cause analysis
Support patch management, STIG compliance, vulnerability remediation, and RMF activities
Collaborate with cybersecurity personnel to ensure compliance with DoD security requirements
Automate system administration and operational tasks using PowerShell, Bash, Python, or Ansible
Support backup, disaster recovery, continuity of operations, and high-availability solutions
Participate in system upgrades, migrations, and technology refresh initiatives
Provide Tier III escalation support for complex infrastructure issues
Mentor junior engineers and contribute to technical strategy and process improvement initiatives
Required Qualifications Bachelor's degree in Information Technology, Computer Science, Engineering, or related field (or equivalent experience)
8+ years of systems engineering or enterprise infrastructure experience
Experience supporting DoD or federal government environments
Strong experience with:
Red Hat Enterprise Linux
VMware vSphere/ESXi administration
Active Directory, DNS, DHCP, Group Policy
Enterprise storage and backup technologies
Automation and scripting tools
Systems monitoring and performance management
Understanding of RMF, STIGs, ACAS, and DoD cybersecurity policies
Active Security+ CE or equivalent DoD 8570/8140 certification
Active Secret clearance required

Preferred Qualifications VMware VCP, Microsoft, Red Hat, or AWS certifications
Experience with hybrid cloud environments and automation frameworks
Familiarity with DevSecOps methodologies and infrastructure-as-code
Experience supporting large-scale enterprise or mission systems within DISA environments
Knowledge of Kubernetes, containers, or modern platform engineering concepts

Desired Skills Strong analytical and troubleshooting abilities
Excellent written and verbal communication skills
Ability to work independently in fast-paced mission environments
Strong customer engagement and stakeholder coordination experience
Proven ability to manage competing priorities and operational deadlines