Senior Cybersecurity Engineer

Mirion is hiring a Senior Cybersecurity Engineer for onsite work in Carrollton, TX (contract). In this role, you will own end-to-end delivery of secure command-and-control systems in critical infrastructure environments using a Standard V-Model approach. You will help shape secure architectures, integrate cybersecurity capabilities into platform environments, and support validation through deployment, turnover, and continuous improvement across the system lifecycle.

Responsibilities

• Translate customer cybersecurity needs into traceable system-level and component-level specifications using the Standard V-Model, working with Project Engineering Leads.
• Contribute to engineering cost estimates based on project requirements and communicate requirements-related issues and risks to program leadership and customers.
• Design cybersecurity architectures for AIM SCS and COTS-based command-and-control solutions, including network segmentation, access control, encryption, secure communications, and integration of physical security subsystems; ensure design decisions are traceable to NEI 08-09 and CIS benchmark controls.
• Architect platform environments of 20–30 Windows servers and workstations within an Active Directory domain, defining Group Policy security controls, virtualized cluster layouts, storage systems, Linux-based security appliances, network switches, and firewalls.
• Create and maintain complete design documentation, including virtual and network design plans, network architecture diagrams, configuration specifications, and cybersecurity control mapping matrices, with full traceability to system requirements.
• Stand up, configure, and deliver Active Directory domain environments of 20–30 servers and workstations.
• Perform server and network deployment across the product delivery lifecycle to prioritize deliverables, validate feature sets, and maintain schedule and budget alignment.
• Integrate COTS solutions using system hardening, vulnerability analysis, documentation, and patching.
• Analyze and resolve integration issues with documented resolution paths.
• Maintain configuration management records throughout the build to preserve an audit trail of decisions, changes, and deviations.
• Verify functional and cybersecurity capabilities against acceptance criteria prior to formal test completion.
• Collaborate on cybersecurity test procedures mapped through a Requirements Traceability Matrix (RTM), validating component and system-level compliance.
• Support Acceptance Testing, including vulnerability assessments and security scans, and dispositioning findings.
• Support onsite deployment: physical installation, network commissioning, Active Directory integration, and system configuration aligned to site-specific cybersecurity commissioning procedures.
• Conduct Site Acceptance Testing (SAT) in coordination with customer security, IT/OT, and operations staff, diagnosing and resolving site-specific issues in real time and communicating technical status, results, and dispositions.
• Train facility personnel on system operation, cybersecurity maintenance, and configuration management practices, delivering turnover packages.
• Travel up to 25%.
• Drive continuous improvement by capturing lessons learned after each delivery and updating design standards, integration procedures, and test methodologies; share knowledge across the organization.
• Mentor junior engineers and act as a technical point of contact for direct customer communications.
• Other duties as required.

Requirements

• Bachelor’s degree in Cybersecurity, Systems Engineering, Computer Science, Electrical Engineering, Information Technology, or a related discipline.
• 5 to 7 years of hands-on experience.
• Strong verbal and written communication skills, including the ability to produce formal engineering documentation and present technical content to varied audiences.
• Knowledge of engineering methodologies.
• U.S. citizenship or permanent resident status required.
• Ability to obtain site access credentials at nuclear power plants and government facilities.

Technology Stack

• Standard V-Model, NEI 08-09, CIS benchmark controls
• AIM SCS, COTS
• Windows servers, Windows workstations, Active Directory, Group Policy
• Virtualized cluster layouts, Linux-based security appliances, network switches, firewalls
• Requirements Traceability Matrix (RTM)
• NIST SP 800-82, NIST SP 800-53, IEC 62443, NRC 10 CFR 73.54

Preferred

• Experience in project-based work with requirements-driven deliverables.
• Networking protocols and small to mid-sized network design.
• Virtualized clusters.
• Direct experience delivering systems in nuclear power, defense, or other NRC/DOE/DOD-regulated environments, including familiarity with nuclear communications systems, terminology, and NRC 10 CFR 73.54 compliance processes.
• CISSP or equivalent certification; GICSP, Security+, or CASP+.
• Familiarity with NIST SP 800-82, NIST SP 800-53, and IEC 62443 standards for industrial and critical infrastructure cybersecurity.