Senior Information Systems Security Officer (ISSO)

Global Dimensions, LLC•Washington, DC

About The Position

Global Dimensions is seeking a highly experienced Senior Information Systems Security Officer to support mission-critical cybersecurity and information assurance requirements for an Intelligence Community customer. The role is based in Annapolis Junction, Maryland; Washington, DC; or Reston, Virginia. The Senior ISSO will strengthen enterprise security, ensure regulatory compliance, manage cybersecurity risks, and support authorization and continuous monitoring of complex information systems. The position oversees and supports Risk Management Framework (RMF) processes, security assessments, compliance activities, and Authorization to Operate (ATO) efforts throughout the system development life cycle. It requires extensive expertise in NIST SP 800-53 security controls, ICD 503, XACTA, Zero Trust architecture, and cloud-native security environments, along with advanced technical judgment and the ability to collaborate with cybersecurity professionals, system owners, developers, and government stakeholders.

Requirements

U.S. citizenship is required due to the sensitivity of customer-related requirements.
Active Top Secret/Sensitive Compartmented Information (TS/SCI) clearance with an active Counterintelligence (CI) Polygraph is required.
Eighteen years of professional experience in information security, cybersecurity, systems engineering, or a closely related technical field with comparable responsibilities and scope; education may substitute for experience, with a bachelor's degree substituting for four years and a master's degree substituting for six years.
Meet DoD 8570/8140 (formerly 8540) certification requirements, including a current CompTIA Security+ certification or another qualifying IAT Level II or III certification, as applicable.
Demonstrated proficiency with XACTA and RMF, including managing and supporting IATT and ATO processes.
Strong working knowledge of Splunk for security monitoring, event analysis, and compliance-related activities.
Experience conducting technical security assessments and architecture reviews against cybersecurity requirements and frameworks, including ICD 503.
Expertise implementing, assessing, and maintaining NIST SP 800-53 security controls in enterprise information systems.
Extensive experience developing, reviewing, and maintaining SSPs, SAPs, POA&Ms, and other security assessment and authorization artifacts.
Ability to coordinate effectively with ISSMs, ISSEs, system owners, Security Control Assessors, and Authorizing Officials on cybersecurity compliance and authorization requirements.
Strong understanding of information system security principles, risk assessment methodologies, vulnerability management, and continuous monitoring.
Experience supporting security compliance throughout the system development life cycle, including design, development, testing, deployment, and maintenance.
Ability to identify security risks, evaluate technical vulnerabilities, recommend mitigation strategies, and support corrective actions.
Excellent analytical, problem-solving, technical documentation, and communication skills, including the ability to explain complex cybersecurity requirements to technical and nontechnical stakeholders.
Ability to work independently, manage competing priorities, and collaborate in a technical, mission-focused Intelligence Community environment.

Nice To Haves

Previous experience as an ISSO or ISSE supporting government, defense, or Intelligence Community programs.
Experience leading cybersecurity initiatives for large-scale or mission-critical programs, including development and implementation of enterprise security strategies.
Leadership experience managing or coordinating cybersecurity professionals, technical teams, and cross-functional security initiatives.
Experience with cloud-native architectures, Data Platform as a Service environments, and Zero Trust implementations.
Strong understanding of identity and access management, network segmentation, data protection, and secure information flow controls.
Success communicating and collaborating with government customers, program managers, executive leadership, system engineers, and cybersecurity stakeholders.
Experience providing technical leadership, cybersecurity guidance, and strategic recommendations to improve enterprise security posture and regulatory compliance.

Responsibilities

Conduct technical security assessments, vulnerability evaluations, and compliance reviews; identify cybersecurity risks and recommend mitigation strategies.
Support the design, implementation, and continuous improvement of information system security controls, cybersecurity processes, and enterprise security initiatives.
Ensure assigned information systems comply with Intelligence Community security policies, RMF requirements, and federal cybersecurity standards throughout the program life cycle.
Collaborate with application leads, system administrators, database administrators, software developers, and testing teams to integrate security requirements into system design, development, deployment, and maintenance.
Provide technical guidance on incorporating security controls and regulatory requirements into systems from the outset.
Support systems in achieving and maintaining ATO by identifying compliance gaps, coordinating remediation, and maintaining required security documentation.
Plan, coordinate, and support security assessment events, addressing technical inquiries and compliance requirements from ISSMs and Security Control Assessors.
Develop, review, update, and maintain System Security Plans (SSPs), Security Assessment Plans (SAPs), Plans of Action and Milestones (POA&Ms), and other security authorization documentation using XACTA.
Lead and coordinate IATT and ATO activities with cybersecurity teams, system owners, stakeholders, and the Authorizing Official.
Implement, assess, and validate NIST SP 800-53 security controls in cloud-native Data Platform as a Service environments.
Apply Zero Trust principles to enterprise data services, including identity and access management, network segmentation, access restrictions, and data flow controls.
Evaluate IT architectures, system configurations, and security implementations against applicable frameworks, including ICD 503, and recommend corrective actions.
Use Splunk and other approved security monitoring tools to review system activity, support assessments, and identify potential security concerns.
Coordinate with ISSMs, ISSEs, system owners, developers, and government security representatives to resolve compliance issues and support authorization decisions.
Monitor and track security findings, vulnerabilities, remediation activities, and POA&M milestones to ensure timely resolution and sustained compliance.
Provide cybersecurity expertise, technical recommendations, and security status updates to program leadership, government stakeholders, and engineering teams.
Support continuous monitoring and improvements to system security posture, operational resilience, and cybersecurity risk management practices.