Cybersecurity Engineer – Classified Infrastructure (Customer Success)

Istari Digital delivers a model-based digital engineering platform used by defense and aerospace organizations. They are hiring a Cybersecurity Engineer to support customer deployments in classified environments, ensuring the platform operates securely and reliably in real-world mission systems.

Responsibilities:

• Deploy and secure Istari’s platform in:
• SIPR, JWICS, and air-gapped environments
• Implement and validate:
• DISA STIGs
• NIST 800-53 / 800-171 controls
• Perform hands-on security work, including:
• System hardening (Windows & Linux)
• Vulnerability scanning (ACAS/Nessus)
• STIG validation and remediation
• POA&M management
• Design, configure, or support secure network architectures, including:
• Segmentation, boundary defense, and routing in classified environments
• Troubleshoot and resolve:
• Security configuration issues
• Connectivity and compliance blockers
• Work directly with:
• Customer security teams (ISSO, ISSM, AO, SCA)
• Program and infrastructure teams
• Provide feedback to engineering on:
• Real-world deployment constraints
• Security gaps and improvements

Requirements:

• Active TS clearance with SCI eligibility
• Security+ (required) — CISSP, CISM, or CASP+ preferred
• 4+ years of hands-on experience in cybersecurity, system administration, or network engineering
• Direct experience with: NIST 800-53 / 800-171
• DISA STIGs
• Experience operating in: Classified environments (SIPR, JWICS, SAP)
• Strong experience securing: Windows and/or Linux systems
• Hands-on System Patching, STIG implementation and validation
• Experience running scans, remediating findings, and managing POA&Ms
• Experience designing or supporting: Secure network architectures in classified environments
• Knowledge of: Network segmentation, boundary defense, and secure connectivity
• Familiarity with STIGs for network devices and infrastructure