Information System Security Engineer (ISSE) Senior - Top Secret Clearance Required

About Agile Defense At Agile Defense we know that action defines the outcome and new challenges require new solutions. That’s why we always look to the future and embrace change with an unmovable spirit and the courage to build for what comes next. Our vision is to bring adaptive innovation to support our nation's most important missions through the seamless integration of advanced technologies, elite minds, and unparalleled agility—leveraging a foundation of speed, flexibility, and ingenuity to strengthen and protect our nation’s vital interests.
Requisition #: 1929 Job Title: Information System Security Engineer (ISSE) Senior Location: Quantico, VA Clearance Level: Top Secret Clearance Required Required Certification(s): One of the following: CCISO, CISA, CISM, CISSO, CISSP, CISSP-ISSEP, CPTE, CySA+, FITSP-A, GCSA, GSLC, or GSNA

Job Description

Agile Defense is seeking a skilled Information System Security Engineer (ISSE) to support the FBI under Objective 2: ISSO/ISSE Program Management. The ISSE will provide technical security engineering expertise to help develop, implement, and sustain a methodology for categorizing FBI IT systems based on architecture, complexity, hosting environment, security posture, and mission requirements.

This role supports the technical analysis needed to differentiate systems by risk, technology stack, overlays, and operational dependencies, and to ensure those categorizations effectively inform labor allocation, reporting, and cost recovery. The ISSE will work closely with ISSOs, system owners, architects, and program leadership to maintain a scalable and compliant categorization framework aligned with FBI and federal standards.

Key Responsibilities:

Support design and maintenance of a methodology to categorize FBI IT systems based on:
Architecture and technology stack
Security classification level
FIPS-199 impact level
National Security System designation
Hosting environment (on-premises, Azure, AWS)
CNSS 1253 overlays
Data sensitivity and data types
Mission/business function
System complexity and integration dependencies

Assess system architecture, interfaces, hosting models, and security control implications to help determine appropriate ISSO/ISSE support levels.

Analyze traditional, hybrid, and cloud-based systems to distinguish technical support requirements.

Support accurate grouping of systems based on risk, operational impact, engineering effort, and compliance obligations.

Translate technical system attributes into labor mapping recommendations aligned to ITSSS labor categories and seniority levels.

Partner with ISSOs and program leadership to ensure categorization decisions are technically sound, repeatable, and well documented.

Contribute to documentation supporting system assignments, engineering rationale, and support models.

Support chargeback and cost recovery efforts by aligning technical support effort with system and division-level reporting.

Assist with automated or semi-automated workflows used for categorization, reporting, and cost assignment.

Support updates to reporting tools and technical logic when policy, technology, or organizational changes occur.

Contribute to RMF and system security engineering activities, including:
Security architecture reviews
Control implementation analysis
Inheritance considerations
Boundary analysis
System interconnection analysis
Technical documentation support

Review and apply NIST, CNSS, and FBI guidance to ensure methodology remains compliant and current.
Support continuous improvement of the categorization framework as new technologies and requirements emerge.

Education and Background

Bachelor's degree in Information Security, Engineering, or related field.

8+ years of experience, or equivalent relevant work experience; e.g., each year of work experience may be substituted for each year of education required.

One of the following certifications: CCISO, CISA, CISM, CISSO, CISSP, CISSP-ISSEP, CPTE, CySA+, FITSP-A, GCSA, GSLC, or GSNA 

Required Skills

- Active Top Secret clearance required.

- Experience assessing complex systems for security architecture, control implementation, and risk categorization. 

- Strong knowledge of: 

- FIPS-199 

- NIST SP 800-37 

- NIST SP 800-53 

- CNSS 1253 

- RMF 

- System security engineering principles 

- Experience with on-premises and cloud environments, including Azure, AWS, or hybrid enterprise systems. 

- Experience supporting technical security documentation and system authorization packages. 

- Ability to analyze diverse technical architectures and map findings to staffing, security, and compliance requirements. 

- Strong communication skills with the ability to explain technical issues to technical and non-technical stakeholders. 

Preferred Skills

- Experience supporting FBI, DOJ, DoD, IC, or other federal national security customers. 

- Experience with classified systems, cross-domain solutions, or National Security Systems. 

- Experience using GRC platforms or structured repositories for system and security data. 

- Familiarity with automation, workflow orchestration, or reporting tools supporting cybersecurity operations. 

In addition, Agile Defense invests in its employees beyond just compensation. Agile’s benefits offerings include, dependent upon position, Health Insurance, Life Insurance, Paid Time Off, Holiday Pay, short-term and long-term Disability, Retirement and Learning and Development opportunities as well as other optional benefit elections.
Our Core Values Employees of Agile Defense are our number one priority, and the importance we place on our culture here is fundamental. Our culture is alive and evolving, but it always stays true to its roots. Here, you are valued as a family member, and we believe that we can accomplish great things together. Agile Defense has been highly successful in the past few years due to our employees and the culture we create together. What makes us Agile? We call it the 6Hs, the values that define our culture and guide everything we do. Together, these values infuse vibrancy, integrity, and a tireless work ethic into advancing the most important national security and critical civilian missions. It's how we show up every day. It's who we are.

• Happy - Be Infectious. Happiness multiplies and creates a positive and connected environment where motivation and satisfaction have an outsized effect on everything we do.
• Helpful - Be Supportive. Being helpful is the foundation of teamwork, resulting in a supportive atmosphere where collaboration flourishes, and collective success is celebrated.
• Honest - Be Trustworthy. Honesty serves as our compass, ensuring transparent communication and ethical conduct, essential to who we are and the complex domains we support.
• Humble - Be Grounded. Success is not achieved alone, humility ensures a culture of mutual respect, encouraging open communication, and a willingness to learn from one another and take on any task.
• Hungry - Be Eager. Our hunger for excellence drives an insatiable appetite for innovation and continuous improvement, propelling us forward in the face of new and unprecedented challenges.
• Hustle - Be Driven. Hustle is reflected in our relentless work ethic, where we are each committed to going above and beyond to advance the mission and achieve success.

Equal Opportunity Employer/Protected Veterans/Individuals with Disabilities