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Mantis Security

Cybersecurity consulting and zero-trust architecture services

Information Systems Security Engineer - ISSE

Full-Time
No salary listed
Senior, Expert
Bachelor's, Master's
Reston, VA, USA
In Person
CybersecuritySecurity Engineering & Architecture
No H1B Sponsorship
US Citizenship, US Top Secret Clearance Required

About the job

Requirements
  • U.S. citizenship is required.
  • Eight years of relevant experience and a bachelor's degree in Computer Science, Information Assurance, Information Security System Engineering, or a related discipline are required; a master's degree may substitute for two years of additional experience, and four additional years of ISSE experience may substitute for a bachelor's degree.
  • DoD 8570 compliance with IASAE Level 3 is required.
  • Three years of experience with scripting languages, Linux or Red Hat, and/or networking appliances are required.
  • Information Systems Security Engineering Professional and Certified Information Systems Security Professional certifications are required.
  • An active Top Secret/Sensitive Compartmented Information security clearance and the ability to obtain a polygraph are required.
Responsibilities
  • Develop and implement security designs that ensure hardware, operating systems, and software applications address cybersecurity requirements and the Security Controls Traceability Matrix.
  • Identify vulnerabilities and noncompliance with Information Assurance standards and regulations, and recommend mitigation strategies.
  • Implement and validate Security Technical Implementation Guide requirements and perform Security Requirements Guide assessments for development and implementation projects.
  • Develop, customize, and configure Splunk applications and dashboards.
  • Develop Security Test Procedures, conduct self-assessments, and support authorization and assessment testing and validation of security designs.
  • Conduct risk analysis by reviewing ACAS, Common Vulnerabilities and Exposures, plugins, and Common Weakness Enumerations; collaborate with system administrators to mitigate vulnerabilities and author Plans of Actions and Milestones as needed.
  • Execute continuous monitoring efforts, respond to data calls and scan requests, and complete weekly and monthly security metrics reporting.
  • Validate that control implementations enforce required data access and network flow restrictions in alignment with the continuous monitoring strategy.
  • Participate in Agile Planning Events and provide technical input.
  • Support government activities and reporting to appropriate Intelligence Community and Department of Defense authorities.
  • Support security authorization activities in compliance with the customer Information System Certification and Accreditation Process, the National Institute of Standards and Technology Risk Management Framework, CNSSI No. 1243, and other prescribed security engineering processes.
  • Assist architects and systems developers in identifying and implementing information security functionality that ensures consistent application of agency security policy and enterprise solutions.
  • Apply system security engineering expertise across security design, engineering life cycle, information domains, cross-domain solutions, cryptography, identification, authentication, authorization, system integration, risk management, intrusion detection, contingency planning, incident handling, configuration control, change management, auditing, certification and accreditation, Information Assurance principles, and security testing.
Desired Qualifications
  • Experience implementing mitigation strategies, resolving problems, and retesting or reevaluating systems.
  • Experience implementing DISA Security Technical Implementation Guides and using Security Content Automation Protocol tools.
  • Working knowledge of server administration and system and application security threats and vulnerabilities.
  • Experience extending applications for security, monitoring, task automation, continuous integration, deployment, and performance optimization.
  • Experience writing scripting or programming projects using Shell scripting, Python, JavaScript, or PowerShell in Linux or Windows environments to support cybersecurity tools and applications.
  • Experience providing guidance on vulnerability and malware remediation.
  • Experience analyzing vulnerabilities, establishing cause and impact, and identifying corrective actions to eliminate and prevent recurrence.

About the company

Mantis Security provides cybersecurity consulting for government and regulated industries, protecting information across the system lifecycle. It delivers C-level strategy, Zero Trust design, RMF/FISMA support, security architecture and engineering, IaC-based IT security automation, and cloud engineering for AWS government and DoD/IC regions. It applies data science and AI/ML to telemetry data to detect risks and speed cyber operations decisions. Led by veterans with intelligence community and DoD experience, its goal is to enable secure, compliant, and efficient cyber operations that reduce risk and accelerate mission readiness.

Company Size

11-50

Company Stage

N/A

Total Funding

N/A

Headquarters

Sarasota, Florida

Founded

2015

Simplify Jobs

Simplify's Take

What believers are saying

  • Careers pages updated September 2026 show active hiring across eight technical roles.
  • Demand aligns with zero trust, RMF, cloud, and DevSecOps work in federal IT.
  • Specialized cleared staffing in Reston and Herndon supports sticky contracts and referral hiring.

What critics are saying

  • We found no recent press releases or award wins; growth looks opaque.
  • Customer concentration stays heavy in Intelligence Community, DoD, and federal agencies.
  • A 2026 schedule slip or recompete loss on GSA contract 47QTCA21D0042 hits revenue fast.

What makes Mantis Security unique

  • McLean-based, intelligence-community-founded consultancy selling cleared cybersecurity talent to federal agencies.
  • GSA contract 47QTCA21D0042 keeps Mantis Security inside government procurement channels.
  • Openings in 2026 emphasize Cloud, HUMINT, ISSO, and DevOps roles.

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