Information Systems Security Engineer

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. This position will design, secure, integrate, and optimize mission-critical cloud and data solutions within classified environments, combining systems engineering principles, cybersecurity compliance, advanced analytics, and modern data engineering practices. The Systems Engineer will work across secure cloud architectures, ETL pipelines, graph databases, and AI/ML-supporting technologies to deliver scalable, compliant solutions aligned with mission requirements.

• 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 activities 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 Extract, Transform, Load (ETL) pipelines supporting 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.

Required:

• 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

  • Master's degree and at least 6 years of relevant experience, including 2 years of Sponsor experience; OR

  • 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, with Neo4j and Cypher expertise preferred.

• 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 both technical and nontechnical stakeholders.

Desired:

• 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.

Eager to join a team where your skills are valued, your growth is nurtured, and your impact is profound? Look no further than Markon, a premier consulting firm deeply dedicated to advancing our nation's most critical missions.

At Markon, we don't just offer jobs – we offer opportunities for personal and professional transformation. Empowering our employees to lead, innovate, and excel, we foster an environment where new ideas are not just welcomed but celebrated. As a perennial Washington Post Top Workplace, we prioritize the well-being and success of our team members, ensuring they can bring their best selves to work.

Headquartered in Falls Church, Virginia, Markon has garnered national recognition for our unwavering dedication to excellence in serving the intelligence community, as well as federal civilian and defense agencies. Our growing reach extends across 17 states, 116 countries, and 5 continents, where our team of dynamic professionals collaborates to deliver unparalleled program and project management services.

Markon values people and the tremendous impact each individual can make – which is why we’re consistently recognized as one of the best places to work in federal government consulting. Here, you can help solve the nation’s most important challenges, surrounded by colleagues who help you grow, advance, and succeed. We are deeply dedicated to what matters – bringing out the best in each other to advance our clients’ missions.Join us and make a meaningful impact.

Markon is an Equal Opportunity/Affirmative Action Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, pregnancy, sexual orientation, gender identity, national origin, age, protected veteran status, or disability status.