Information Systems Security Engineer (ISSE) (TS/SCI with Poly Required)

GCI Incorporated•Tysons, VA

20h

About The Position

The ISSE will lead and execute security engineering activities across complex, enterprise-scale environments. This role requires deep technical expertise across infrastructure, platforms, and applications, combined with expert-level, hands-on experience implementing the NIST Risk Management Framework (RMF) within federal government environments. The ideal candidate is a technical practitioner, not just an advisor – someone who can design, implement, assess, and secure systems end-to-end while directly supporting system authorization, continuous monitoring, and risk-based decision-making. This role also serves as the technical focal point for all security incidents, leading triage, investigation, and resolution efforts in coordination with program and enterprise security teams. GCI embodies excellence, integrity and professionalism. The employees supporting our customers deliver unique, high-value mission solutions while effectively leverage the technological expertise of our valued workforce to meet critical mission requirements in the areas of Data Analytics and Software Development, Engineering, Targeting and Analysis, Operations, Training, and Cyber Operations. We maximize opportunities for success by building and maintaining trusted and reliable partnerships with our customers and industry. At GCI, we solve the hard problems. As an Information Systems Security Engineer (ISSE), a typical day will include the following duties:

Requirements

Bachelor’s Degree in Computer Science, IT, or a related technical discipline, or the equivalent combination of education, technical training, or work/military experience
Minimum ten (10) years of related cyber security engineering experience
Proven hands-on Cyber Security Engineer SME, not policy-only or audit-only
Comfortable working across network, system, platform, and application layers
Deep understanding of how security controls are actually implemented and validated
Experience in federal RMF-driven environments
Able to bridge security, engineering, and compliance effectively
Experienced in managing security incidents from detection through resolution
Skilled at balancing immediate incident response needs with long-term security improvements
Effective collaborator across organizational boundaries during high-pressure security events
Operate independently as the technical authority for system security engineering
Demonstrate the ability to provide technical hands-on configuration, validation, and assessment of security controls
Translate RMF and NIST requirements into real-world technical implementations
Communicate complex technical security issues clearly to both technical and non-technical stakeholders
Maintain a strong balance between security compliance and operational practicality
Lead rapid response to security incidents with minimal guidance
Demonstrate strong analytical and troubleshooting skills under pressure during active security events
Effectively communicate incident status, impact, and remediation progress to technical and leadership audiences
Expert-level experience with NIST Risk Management Framework (RMF) in federal government environments
Strong knowledge of: NIST SP 800-53 NIST SP 800-37 NIST SP 800-30
Direct involvement I ATO packages, control implementation, and assessments
Hands-on experience with Security Information and Event Management (SIEM) platforms (e.g., Splunk, ELK Stack, ArcSight, QRadar)
Demonstrated experience in security incident detection, analysis, and response
Proven ability to triage security alerts and determine criticality and impact
Networking (e.g., routing, switching, firewalls, load balancers, network security controls)
Operating Systems: Windows Server Linux (RHEL, CentOS)
Virtualization and storage platforms
Databases (SQL and/or NoSQL)
Data platforms (e.g., HPCC, Hadoop/Cloudera)
Web services, APIs, and application architectures
Software development environments and CI/CD pipelines
Security tooling (e.g., vulnerability scanners, endpoint protection, SIEM)
Security engineering and system hardening
Vulnerability discovery and remediation
Secure system design and architecture reviews
Technical documentation supporting RMF compliance
Experience in cloud environments (AWS, Azure, GCP, CI) within federal RMF contexts
Experience with DevSecOps practices
A candidate must be a US Citizen and requires an active/current TS/SCI with Polygraph clearance.

Nice To Haves

Hands-on experience with containerization and orchestration (Docker, Kubernetes)
Hands-on experience with infrastructure-as-code
Knowledge of federal overlays (e.g., DoD, FISMA High/Moderate)
Relevant certifications (preferred, not required): CISSP CAP CISM Security+ Cloud Security Certified Ethical Hacker
Experience with guiding and directing junior engineers and information systems security officer (ISSO)
Experience with security orchestration, automation, and response (SOAR) platforms
Background in threat hunting and proactive security monitoring
Relevant incident response certifications

Responsibilities

Serve as the Cyber Security Engineer SME, providing hands-on security engineering across all system layers (infrastructure, platform, and application)
Engineer, implement, and validate security controls in accordance with NIST SP 800-53 and RMF requirements
Lead and support RMF lifecycle activities (Categorize, Select, Implement, Assess, Authorize, Monitor)
Perform security engineering for: Network architectures and boundary protections Windows and Linux operating systems Storage and virtualization platforms Databases and data platforms Web services, APIs, and application stacks Custom and COTS/GOTS software solutions
Provide technical input to RMF artifacts, including: System Security Plans (SSP) Security Control Assessments (SCA) support POA&Ms Risk assessments and security impact analyses
Collaborate with system owners, architects, developers, ad operations teams to embed security into system design and implementation
Support ATO, re-authorization, and continuous monitoring activities
Identify security risks and provide practical, technically sound mitigation strategies
Participate in security reviews, technical design reviews, and vulnerability remediation efforts
Serve as technical l point of contact for all security incidents affecting the program
Lead triage and analysis of new security alerts from SIEM, IDS/IPS, and other security monitoring tools
Drive remediation efforts for recurring security alerts, identifying root causes and implementing systemic fixes
Coordinate incident response activities between program stakeholders and enterprise security operations
Act as primary liaison between program teams and enterprise security for incident escalation, resolution, and reporting
Perform forensic analysis and technical investigations of security events
Document security incidents, response actions, and lessons learned
Develop and maintain runbooks and playbooks for common security incident types