ISSO​/Security Engineer; TS​/SCI Poly Security Clearance

Position: ISSO/Security Engineer (TS/SCI with Poly Required) with Security Clearance
Job Category: IT Infrastructure and Operations

Requisition Number: ISSOS
002228 Posting Details
* Posted:
July 24, 2026

* Full-Time

* On-site

* Salary Range: $ USD to $ USD Job Details Description 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 ISSO, a typical day will include the following duties: JOB DESECRIPTION Members of the ISSO team support the customer and their assessment and authorization (A&A) of critical systems, detection of adversary behavior, and improving the defensive posture of their information systems. The successful candidate will use various tools and methodologies to evaluate the state of systems and applications for vulnerabilities, verify protection against adversary intent, and evaluate cyber security processes to protect and defend against adversaries.

KEY RESPONSIBILITIES
* Overseeing the security and coordinating risk management by identifying requirements for documentation with system categorization, the System Security Plan (SSP), and systems risk assessment as required under NIST 800-53/53A.

* Function as the go-to person for security questions and needs while supporting the customer in-house as well as external stakeholders.

* Assessing system compliance with NIST requirements and identifying vulnerabilities in systems and evaluating planned remedial actions based upon those requirements.

* Participating in change management by reviewing change requests and assessing the security impact of proposed changes and coordinating those changes with the ISSM.

* Work closely with stakeholders, developers, and external teams including customer security managers (ISSMs), organizational leadership, and key personnel to maintain security posture.

* Knowledge in assessing security considerations for Artificial Intelligence (AI) solutions, including secure deployment, risk management, data protection, and compliance with enterprise cybersecurity requirements.

* Lead comprehensive technical evaluations of cloud-based applications and systems, focusing on secure configurations across PaaS, SaaS, and IaaS environments.

* Strong understanding of cloud providers implementing Amazon Web Services (AWS), Microsoft Azure, and Oracle Cloud technologies to implement cloud security best practices.

* Utilize audit tools such as Elasticsearch or Splunk SIEMs, and IDS/IPS for monitoring and alerting.

* Utilize industry-standard vulnerability assessment tools such as Rapid7, Nessus, and Web Inspect to identify, analyze, and remediate system and application vulnerabilities

* Work closely with Common Control Provider (CCP) requirements and methodology.
EDUCATION AND EXPERIENCE
* Bachelors degree in computer engineering, compute science, cybersecurity, or a similar degree, or 5-8 years of relevant work experience.

* 5 years of demonstrated cybersecurity expertise.
REQUIRED QUALIFICATIONS
* Experience assisting the customer with decisions impacting the security posture and compliance of their systems and networks with requirements as documented in NIST 800-53 and its revisions.

* Verbal and written communication skills that demonstrate technical cybersecurity concepts in a clear and concise manner.

* Support control implementation assessment and reporting and monitoring process using cybersecurity and assessment management systems.

* Ability to work both independently and in a team environment.
DESIRED QUALIFICATIONS
* Demonstrated history of technical aptitude with vulnerability and risk assessment tools

* Strong understanding of methodologies for researching and documenting software and hardware vulnerabilities

* Demonstrated skill documenting process and procedures in CONOPS, system security, contingency, configuration management and other plans

* Knowledge of the customer’s organization, network systems, processes and procedures

* A candidate must be a US Citizen and requires an active/current TS/SCI with Polygraph clearance. Equal Opportunity Employer / Individuals with Disabilities / Protected Veterans Qualifications Skills Behaviors :
Motivations :
Education Preferred Bachelor of Science or better in Computer Engineering or related field. Experience Required 5 years:
Demonstrated cybersecurity expertise. 15 years:
Work related experience. Licenses & Certifications Equal Opportunity Employer