Information Systems Security Engineer

Markon•Chantilly, VA

1d•$175,000 - $205,000•Onsite

About The Position

Markon is seeking an experienced Systems Engineer specializing in Information Systems Security Engineering (ISSE) and Data Engineering to support an Intelligence Community client in Chantilly, Virginia. The role designs, secures, integrates, and optimizes mission-critical cloud and data solutions in classified environments, combining systems engineering, cybersecurity compliance, advanced analytics, and data engineering. Work spans secure cloud architectures, ETL pipelines, graph databases, and AI/ML-supporting technologies, delivering scalable solutions aligned with mission requirements. The position supports secure cloud and on-premises environments, classified mission systems, and accreditation requirements. The engineer collaborates with systems engineers, developers, security teams, and mission stakeholders, and participates in Agile development and CI/CD processes. The listed salary range is USD $175,000 to $205,000 per year; Markon notes that the range is a general guideline and not a compensation guarantee.

Requirements

Active TS/SCI clearance with Full Scope Polygraph (FSP).
Bachelor's degree and at least 8 years of relevant experience, including 2 years of Sponsor experience; or a master's degree and at least 6 years of relevant experience, including 2 years of Sponsor experience; or a PhD and at least 3 years of relevant experience, including 2 years of Sponsor experience.
An additional 4 years of relevant experience may be considered in lieu of a degree.
Demonstrated experience designing, securing, and maintaining data flow solutions within classified or high-security environments.
Strong ISSE experience, including security architecture, A&A/ATO processes, vulnerability management, accreditation documentation, and continuous monitoring.
Hands-on experience developing ETL pipelines, data models, activity models, and data engineering solutions supporting AI/ML initiatives.
Proficiency in at least one programming language, such as Cypher, Python, Java, or JavaScript.
Experience with graph database technologies.
Experience cleaning, modeling, analyzing, and visualizing medium-to-large datasets.
Experience supporting Sponsor mission systems or classified programs.
Strong written and verbal communication skills, with the ability to explain complex technical concepts to technical and nontechnical stakeholders.

Nice To Haves

Neo4j and Cypher expertise.
Experience with enterprise data strategy, data governance, data stewardship, and metadata management.
Experience developing dashboards, technical visualizations, or system-level data representations.
Exposure to AI/ML and large language model (LLM) systems, including associated data engineering workflows.
Familiarity with Agile development methodologies and cloud-native architecture patterns.
Hands-on experience with Neo4j graph databases and advanced Cypher query development.

Responsibilities

Lead Information Systems Security Engineering (ISSE) activities throughout the system lifecycle, including security architecture development, security control implementation, and compliance with NIST and Sponsor-specific requirements.
Develop and maintain Assessment and Authorization (A&A) documentation supporting Authorization to Operate (ATO), including System Security Plans (SSPs), Plans of Action and Milestones (POA&Ms), test procedures, and continuous monitoring artifacts.
Conduct security scans, vulnerability assessments, patch management, and remediation across classified cloud and on-premises environments.
Integrate security-by-design principles into system architectures, data flows, ETL pipelines, and operational workflows.
Design, develop, and optimize ETL pipelines for enterprise data integration, advanced analytics, and AI/ML initiatives.
Develop and maintain Neo4j graph database solutions, including data modeling, relationship mapping, schema optimization, and Cypher query development.
Clean, preprocess, analyze, and visualize medium-to-large datasets to support mission analysis and operational decision-making.
Develop secure software components using technologies such as Cypher, Python, Java, and JavaScript.
Perform technical and functional assessments, risk analysis, cost estimation, trade studies, and systems engineering evaluations.
Support secure cloud architectures, virtualization technologies, and scalable data solutions within mission environments.
Collaborate with systems engineers, developers, security teams, and mission stakeholders to ensure solutions meet technical, accreditation, and operational requirements.
Participate in Agile development activities, including sprint planning, iterative development, and CI/CD processes.
Maintain comprehensive documentation covering technical requirements, data models, engineering decisions, software components, and security compliance.