Cybersecurity Engineer – Classified Infrastructure (Customer Success)

Security Clearance: Active TS required with SCI eligibility (Polygraph a plus)

About Istari Digital

Istari Digital delivers a model-based digital engineering platform used by defense and aerospace organizations to design and operate mission-critical systems. Our platform is deployed into classified and high-security environments, where cybersecurity is foundational—not optional.

Role Overview

We are hiring a Cybersecurity Engineer to support customer deployments in classified environments, ensuring Istari’s platform operates securely, compliantly, and reliably in real-world mission systems.

This role sits within Customer Success and focuses on hands-on system and infrastructure security—not just documentation or policy.

Depending on your background, you may lean more toward:

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System hardening (Windows/Linux)

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Secure network infrastructure (classified environments)

In this role YOU will be the difference between a platform that looks secure on paper, and one that actually works inside real classified mission environments.

What You'll Do:
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Deploy and secure Istari’s platform in:

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SIPR, JWICS, and air-gapped environments

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Implement and validate:

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DISA STIGs

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NIST 800-53 / 800-171 controls

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Perform hands-on security work, including:

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System hardening (Windows & Linux)

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Vulnerability scanning (ACAS/Nessus)

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STIG validation and remediation

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POA&M management

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Design, configure, or support secure network architectures, including:

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Segmentation, boundary defense, and routing in classified environments

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Troubleshoot and resolve:

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Security configuration issues

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Connectivity and compliance blockers

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Work directly with:

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Customer security teams (ISSO, ISSM, AO, SCA)

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Program and infrastructure teams

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Provide feedback to engineering on:

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Real-world deployment constraints

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Security gaps and improvements

Required Qualifications:
Must-Haves

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Active TS clearance with SCI eligibility

Security+ (required) — CISSP, CISM, or CASP+ preferred

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4+ years of hands-on experience in cybersecurity, system administration, or network engineering

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Direct experience with:

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NIST 800-53 / 800-171

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DISA STIGs

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Experience operating in:

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Classified environments (SIPR, JWICS, SAP)

Your Background (You may come from one or both areas)

Experience Profile A: System Hardening (System Administration)

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Strong experience securing:

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Windows and/or Linux systems

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Hands-on System Patching, STIG implementation and validation

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Experience running scans, remediating findings, and managing POA&Ms

Experience Profile B: Secure Infrastructure (Network Engineering)

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Experience designing or supporting:

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Secure network architectures in classified environments

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Knowledge of:

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Network segmentation, boundary defense, and secure connectivity

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Familiarity with STIGs for network devices and infrastructure

What Makes You a Strong Fit:
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You started in a technical role (SysAdmin, Network, SOC) and moved into security

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You’ve done real, hands-on work—not just compliance oversight

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You’re comfortable working:

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In deploying emerging technology into real-world classified environments

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Under time pressure to meet deployment or mission deadlines

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You stay long enough to see systems through deployment and accreditation

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You’re comfortable in a startup environment—scrappy, fast-moving, and collaborative

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You’re willing to do the work needed to get across the finish line, even when it’s manual