ISSE (Information Systems Security Engineer) with Security Clearance

Position Title: Information Systems Security Engineer (ISSE)
Location: Hybrid: Chantilly (3 days/week)/Remote (2 days/week) Clearance Required: TS/SCI with Full Scope Polygraph
Duration: 3-4 month assignment, 40/hours a week Position Summary:
The Britton Group is seeking a highly motivated Information Systems Security Engineer (ISSE) to support mission-critical systems within the Intelligence Community (IC) on a short term assignment to assist a critical customer for approximately 3-4 months, full-time (40/hours week) with the potential for longer term. The ISSE will serve as the security engineering lead on systems operating in a collaborative Agile development environment, ensuring compliance with security frameworks and alignment with A&A, compliance, and continuous monitoring processes. This role emphasizes secure system development, logging, and lifecycle compliance in an Agile delivery model.

Key Responsibilities:

• Lead and support the Assessment & Authorization (A&A) process in accordance with ICD 503, NIST Risk Management Framework (RMF), and sponsor policies.

• Partner closely with Agile development teams to integrate security requirements into sprint cycles, planning, and delivery.

• Develop and maintain System Security Plans (SSPs), Risk Assessments, Security Control Traceability Matrices (SCTMs), and Plan of Action & Milestones (POA&Ms).

• Design, implement, and monitor security logging, auditing, and incident response capabilities (e.g., Splunk, ELK Stack).

• Ensure compliance with applicable NIST 800-53 controls, STIGs, and customer-specific policies throughout system iterations.

• Conduct security architecture reviews, participate in sprint retrospectives, and advise on secure coding and deployment practices.

• Support continuous integration/continuous delivery (CI/CD) pipelines with security validation steps.

• Collaborate with developers, ISSOs, system engineers, and product owners to maintain alignment between security, operational, and functional priorities.

• Perform vulnerability scanning and remediation tracking.

• Maintain up-to-date knowledge of cybersecurity trends, threats, tools, and compliance expectations in support of dynamic, evolving systems.

Basic Qualifications:

• Active TS/SCI with Full Scope Polygraph.

• Bachelor's degree in Computer Science, Cybersecurity, or related technical field (or equivalent experience).

• 5+ years of cybersecurity experience, with at least 3 years in an ISSE role supporting classified or government systems.

• Strong understanding of NIST RMF, ICD 503, and federal cybersecurity policy.

• Experience operating in or supporting Agile/Scrum-based development environments.

• Proficiency in securing Windows and Linux systems.

• Knowledge of security engineering principles, A&A packages, and system lifecycle documentation.

• Familiarity with logging, SIEM integration, and auditing requirements.

• Working knowledge of security compliance tools and techniques (e.g., STIG Viewer, SCAP, Nessus).

Preferred Qualifications:

• Industry certifications such as CISSP, CAP, Security+, or CEH.

• Experience securing cloud-based systems (AWS C2S, GovCloud, Azure IL environments).

• Familiarity with DevSecOps, infrastructure as code, and secure automation.

• Knowledge of Zero Trust Architecture, cross-domain solutions, or tactical networks.

• Ability to brief stakeholders and document security posture in fast-paced Agile delivery cycles.

Why The Britton Group?
The Britton Group is a trusted provider of advanced national security and intelligence solutions. We specialize in protecting critical systems through secure engineering, mission-focused support, and agile delivery. Join our team and contribute to meaningful, high-impact work that safeguards national interests. The Britton Group offers competitive salaries and a top-notch benefits package that
includes:
6% 401K match with immediate vesting
100% company paid Medical, Dental, Vision benefits for employee only coverage
Company paid for STD, LTD and Basic Life and AD&D Insurance
11 paid holidays + 20 days PTO (increases with tenure)
Tuition reimbursement of up to $5,250/year, as well as training allowances
Competitive referral bonuses for employees