8,084 System Security jobs in the United States

• Design and implement secure system architectures
• Monitor and respond to system security incidents
• Develop and enforce system security policies
• Conduct risk assessments and mitigate vulnerabilities
• Ensure compliance with security standards and frameworks
• Collaborate with teams to integrate security into system development

• Proficiency in configuring firewalls and intrusion detection systems
• Strong knowledge of operating system security (e.g., Linux, Windows)
• Experience with endpoint protection tools
• Familiarity with network protocols and security
• Ability to perform vulnerability assessments and penetration tests
• Expertise in implementing encryption and secure authentication methods

• Knowledge of cloud security practices (e.g., AWS, Azure)
• Familiarity with automation tools for security (e.g., Ansible, Terraform)
• Experience with security incident response and forensics
• Understanding of DevSecOps principles
• Strong communication and technical documentation skills
• Ability to train and mentor team members on security best practices

• Excellent Salaries
• Flexible Work Schedule
• Cafeteria Style Benefits
• 10% - 401k Matching (Vested Immediately)
• Additional 401k Profit Sharing
• 30 days Paid Leave/Holiday (No Use or Lose!)
• The day off for your birthday
• Medical/Dental/Vision - 100% employee coverage. ($1200 allowance - or a bonus)
• HSA/FSA
• AFLAC
• Long Term/Short Term Disability - 100% employee coverage. No cost to you.
• Life Insurance - 100% employee coverage. No cost to you.
• Additional Discretionary Life Insurance
• Paid Training
• No long, wordy reviews with tons of paperwork!
• Referral bonus program with recurring annual payments

• Design and implement secure system architectures
• Monitor and respond to system security incidents
• Develop and enforce system security policies
• Conduct risk assessments and mitigate vulnerabilities
• Ensure compliance with security standards and frameworks
• Collaborate with teams to integrate security into system development

• Proficiency in configuring firewalls and intrusion detection systems
• Strong knowledge of operating system security (e.g., Linux, Windows)
• Experience with endpoint protection tools
• Familiarity with network protocols and security
• Ability to perform vulnerability assessments and penetration tests
• Expertise in implementing encryption and secure authentication methods

• Knowledge of cloud security practices (e.g., AWS, Azure)
• Familiarity with automation tools for security (e.g., Ansible, Terraform)
• Experience with security incident response and forensics
• Understanding of DevSecOps principles
• Strong communication and technical documentation skills
• Ability to train and mentor team members on security best practices

• Excellent Salaries
• Flexible Work Schedule
• Cafeteria Style Benefits
• 10% - 401k Matching (Vested Immediately)
• Additional 401k Profit Sharing
• 30 days Paid Leave/Holiday (No Use or Lose!)
• The day off for your birthday
• Medical/Dental/Vision - 100% employee coverage. ($1200 allowance - or a bonus)
• HSA/FSA
• AFLAC
• Long Term/Short Term Disability - 100% employee coverage. No cost to you.
• Life Insurance - 100% employee coverage. No cost to you.
• Additional Discretionary Life Insurance
• Paid Training
• No long, wordy reviews with tons of paperwork!
• Referral bonus program with recurring annual payments

• Design and implement secure system architectures
• Monitor and respond to system security incidents
• Develop and enforce system security policies
• Conduct risk assessments and mitigate vulnerabilities
• Ensure compliance with security standards and frameworks
• Collaborate with teams to integrate security into system development

• Proficiency in configuring firewalls and intrusion detection systems
• Strong knowledge of operating system security (e.g., Linux, Windows)
• Experience with endpoint protection tools
• Familiarity with network protocols and security
• Ability to perform vulnerability assessments and penetration tests
• Expertise in implementing encryption and secure authentication methods

• Knowledge of cloud security practices (e.g., AWS, Azure)
• Familiarity with automation tools for security (e.g., Ansible, Terraform)
• Experience with security incident response and forensics
• Understanding of DevSecOps principles
• Strong communication and technical documentation skills
• Ability to train and mentor team members on security best practices

• Excellent Salaries
• Flexible Work Schedule
• Cafeteria Style Benefits
• 10% - 401k Matching (Vested Immediately)
• Additional 401k Profit Sharing
• 30 days Paid Leave/Holiday (No Use or Lose!)
• The day off for your birthday
• Medical/Dental/Vision - 100% employee coverage. ($1200 allowance - or a bonus)
• HSA/FSA
• AFLAC
• Long Term/Short Term Disability - 100% employee coverage. No cost to you.
• Life Insurance - 100% employee coverage. No cost to you.
• Additional Discretionary Life Insurance
• Paid Training
• No long, wordy reviews with tons of paperwork!
• Referral bonus program with recurring annual payments

MANTECH seeks a mission-focused Cybersecurity System Security Engineer III to support Special Access Programs (SAPs) aligned with SSC and AFSPC acquisition initiatives.

In this on-site role located in El Segundo, CA , you will work closely with security professionals to safeguard vital national security systems while ensuring compliance with NIST, DoD, and SAP cybersecurity frameworks.
 

Responsibilities include but are not limited to:
 

You will lead advanced system security engineering initiatives, helping ensure that acquisition systems meet security and accreditation requirements from design through deployment.

• Lead a team of System Security Engineers and Certification & Accreditation Analysts responsible for safeguarding U.S. and allied national security interests. Provide technical direction, policy alignment, and oversight during system design, development, and testing phases.
• Chair or co-chair cybersecurity working groups, represent the Government Program Manager in advisory bodies, and actively participate in SSE IPTs to ensure integration of security across SAP systems.
• Guide the development, implementation, and evaluation of cybersecurity policies. Oversee integration of SAP network infrastructures and provide expert-level consultation across all aspects of information security.
• Review and assess secure system designs, providing risk management recommendations to stakeholders. Ensure compliance with RMF, JSIG, and other relevant accreditation processes.
• Support Mission and Training system development with SSE expertise, including review of system architectures, test and evaluation events, and overall security engineering input throughout the acquisition lifecycle.
• Assist in the development and ongoing maintenance of Program Protection Plans and Cybersecurity Strategies. Support site activations and major security review events.
• Collaborate directly with accreditation authorities to guide systems toward Authorization to Operate (ATO), while managing documentation and continuous compliance throughout system operation.
   

Minimum Qualifications:

• Bachelor’s degree in a related discipline; An additional 4 years of related experience might be substituted for a degree
• 12 + years of relevant experience
• 8 + years supporting SCI or SAR environments
• Must meet position and certification requirements outlined in DoD Directive 8570.01-M for Information Assurance Technician Level 3 and Information Assurance Manager Level 3 within 6 months of the date of hire. CISSP Recommended.
• Strong understanding of RMF and JSIG accreditation processes, as well as legacy frameworks such as DITSCAP and DIACAP
   

Preferred Qualifications:

• Familiarity with key security directives including ICDs, JAFANs, and DoD Manuals
• 4 + years of SAP-relevant experience

Clearance Requirements:

• Current TS/SCI clearance
• Must be eligible for access to Special Access Programs.
• Willingness to submit to a Counterintelligence polygraph is required.
   

Physical Requirements:

• Willingness to travel within the organizational Area of Responsibility (AOR), including air and ground transport as needed
• Must be able to remain in a stationary position approximately 50% of the time using standard or adjustable desks/chairs in secure environments
• Occasionally required to move about the office to access safes, files, and technical equipment, and may assist with the installation or removal of computer components

MANTECH seeks a mission-focused Cybersecurity System Security Engineer III to support Special Access Programs (SAPs) aligned with SSC and AFSPC acquisition initiatives.

In this on-site role located in El Segundo, CA , you will work closely with security professionals to safeguard vital national security systems while ensuring compliance with NIST, DoD, and SAP cybersecurity frameworks.
 

Responsibilities include but are not limited to:
 

You will lead advanced system security engineering initiatives, helping ensure that acquisition systems meet security and accreditation requirements from design through deployment.

• Lead a team of System Security Engineers and Certification & Accreditation Analysts responsible for safeguarding U.S. and allied national security interests. Provide technical direction, policy alignment, and oversight during system design, development, and testing phases.
• Chair or co-chair cybersecurity working groups, represent the Government Program Manager in advisory bodies, and actively participate in SSE IPTs to ensure integration of security across SAP systems.
• Guide the development, implementation, and evaluation of cybersecurity policies. Oversee integration of SAP network infrastructures and provide expert-level consultation across all aspects of information security.
• Review and assess secure system designs, providing risk management recommendations to stakeholders. Ensure compliance with RMF, JSIG, and other relevant accreditation processes.
• Support Mission and Training system development with SSE expertise, including review of system architectures, test and evaluation events, and overall security engineering input throughout the acquisition lifecycle.
• Assist in the development and ongoing maintenance of Program Protection Plans and Cybersecurity Strategies. Support site activations and major security review events.
• Collaborate directly with accreditation authorities to guide systems toward Authorization to Operate (ATO), while managing documentation and continuous compliance throughout system operation.
   

Minimum Qualifications:

• Bachelor’s degree in a related discipline; An additional 4 years of related experience might be substituted for a degree
• 12 + years of relevant experience
• 8 + years supporting SCI or SAR environments
• Must meet position and certification requirements outlined in DoD Directive 8570.01-M for Information Assurance Technician Level 3 and Information Assurance Manager Level 3 within 6 months of the date of hire. CISSP Recommended.
• Strong understanding of RMF and JSIG accreditation processes, as well as legacy frameworks such as DITSCAP and DIACAP
   

Preferred Qualifications:

• Familiarity with key security directives including ICDs, JAFANs, and DoD Manuals
• 4 + years of SAP-relevant experience

Clearance Requirements:

• Current TS/SCI clearance
• Must be eligible for access to Special Access Programs.
• Willingness to submit to a Counterintelligence polygraph is required.
   

Physical Requirements:

• Willingness to travel within the organizational Area of Responsibility (AOR), including air and ground transport as needed
• Must be able to remain in a stationary position approximately 50% of the time using standard or adjustable desks/chairs in secure environments
• Occasionally required to move about the office to access safes, files, and technical equipment, and may assist with the installation or removal of computer components

MANTECH seeks a mission-focused Cybersecurity System Security Engineer III to support Special Access Programs (SAPs) aligned with SSC and AFSPC acquisition initiatives.

In this on-site role located in El Segundo, CA , you will work closely with security professionals to safeguard vital national security systems while ensuring compliance with NIST, DoD, and SAP cybersecurity frameworks.
 

Responsibilities include but are not limited to:
 

You will lead advanced system security engineering initiatives, helping ensure that acquisition systems meet security and accreditation requirements from design through deployment.

• Lead a team of System Security Engineers and Certification & Accreditation Analysts responsible for safeguarding U.S. and allied national security interests. Provide technical direction, policy alignment, and oversight during system design, development, and testing phases.
• Chair or co-chair cybersecurity working groups, represent the Government Program Manager in advisory bodies, and actively participate in SSE IPTs to ensure integration of security across SAP systems.
• Guide the development, implementation, and evaluation of cybersecurity policies. Oversee integration of SAP network infrastructures and provide expert-level consultation across all aspects of information security.
• Review and assess secure system designs, providing risk management recommendations to stakeholders. Ensure compliance with RMF, JSIG, and other relevant accreditation processes.
• Support Mission and Training system development with SSE expertise, including review of system architectures, test and evaluation events, and overall security engineering input throughout the acquisition lifecycle.
• Assist in the development and ongoing maintenance of Program Protection Plans and Cybersecurity Strategies. Support site activations and major security review events.
• Collaborate directly with accreditation authorities to guide systems toward Authorization to Operate (ATO), while managing documentation and continuous compliance throughout system operation.
   

Minimum Qualifications:

• Bachelor’s degree in a related discipline; An additional 4 years of related experience might be substituted for a degree
• 12 + years of relevant experience
• 8 + years supporting SCI or SAR environments
• Must meet position and certification requirements outlined in DoD Directive 8570.01-M for Information Assurance Technician Level 3 and Information Assurance Manager Level 3 within 6 months of the date of hire. CISSP Recommended.
• Strong understanding of RMF and JSIG accreditation processes, as well as legacy frameworks such as DITSCAP and DIACAP
   

Preferred Qualifications:

• Familiarity with key security directives including ICDs, JAFANs, and DoD Manuals
• 4 + years of SAP-relevant experience

Clearance Requirements:

• Current TS/SCI clearance
• Must be eligible for access to Special Access Programs.
• Willingness to submit to a Counterintelligence polygraph is required.
   

Physical Requirements:

• Willingness to travel within the organizational Area of Responsibility (AOR), including air and ground transport as needed
• Must be able to remain in a stationary position approximately 50% of the time using standard or adjustable desks/chairs in secure environments
• Occasionally required to move about the office to access safes, files, and technical equipment, and may assist with the installation or removal of computer components

• Design and implement security solutions for information systems
• Conduct vulnerability assessments and develop mitigation strategies
• Monitor and maintain system security configurations
• Collaborate with teams to integrate security into system designs
• Develop and enforce security policies and procedures
• Ensure compliance with regulatory and organizational security standards

• Proficiency in security tools like SIEM, IDS/IPS, and vulnerability scanners
• Strong knowledge of encryption protocols and techniques
• Expertise in firewalls and network security configurations
• Familiarity with operating systems security (e.g., Windows, Linux)
• Ability to conduct security risk analysis and assessments
• Experience in secure software development practices

• Knowledge of cloud security frameworks (e.g., AWS, Azure)
• Experience with advanced threat detection and response techniques
• Familiarity with DevSecOps practices and automation tools
• Expertise in secure identity and access management (IAM)
• Understanding of zero trust architecture principles
• Hands-on experience with forensics and incident response tools

• Excellent Salaries
• Flexible Work Schedule
• Cafeteria Style Benefits
• 10% - 401k Matching (Vested Immediately)
• Additional 401k Profit Sharing
• 30 days Paid Leave/Holiday (No Use or Lose!)
• The day off for your birthday
• Medical/Dental/Vision - 100% employee coverage. ($1200 allowance - or a bonus)
• HSA/FSA
• AFLAC
• Long Term/Short Term Disability - 100% employee coverage. No cost to you.
• Life Insurance - 100% employee coverage. No cost to you.
• Additional Discretionary Life Insurance
• Paid Training
• No long, wordy reviews with tons of paperwork!
• Referral bonus program with recurring annual payments

MANTECH seeks a motivated, career and customer-oriented Information System Security Engineer (ISSE) to join our team in Quantico, VA

Responsibilities include, but are not limited to:

• Identify information protection needs for an IS and Network Environment. Define IS and Network Environment security requirements in accordance with applicable cybersecurity requirements

• Design security architectures for use within the IS and Network Environment. Design and develop cybersecurity-enabled products for use within an IS and Network Environment

• Integrate and/or implement security with Cross Domain Solutions (CDS) for use within an IS and Network Environment

• Develop and implement security designs for new or existing network system(s). Ensure that the design of hardware, operating systems, and software applications adequately address cybersecurity requirements for the IS and Network Environment

• Design, develop, and implement network security measures that provide confidentiality, integrity, availability, authentication, and non-repudiation. Design, develop, and implement specific cybersecurity countermeasures for the IS and Network Environment

• Develop interface specifications for the IS and Network Environment. Develop approaches to mitigate IS and Network Environment vulnerabilities and recommend changes to network or network system components as needed

• Ensure that network system(s) designs support the incorporation of FBI directed cybersecurity vulnerability solutions

Minimum Qualifications:

• 5+ years' experience, or equivalent education/experience (i.e., Doctorate plus 3 years; Master's plus 3 years; Associates plus 7 years; or H.S./GED plus 14 years)

• Hold at least one of the following certifications: Certified Information Systems Security Professional (CISSP) (or Associate), CompTIA Advanced Security Practitioner (CASP) CE, Certified Secure Software Lifecycle Professional (CSSLP), CISSP- Information System Security Engineering Professional (ISSEP), or CISSP- Information System Security Architecture Professional (ISSAP).

• Familiarity with the use and operation of security tools including: Tenable Nessus and/or Security Center, IBM Guardium, HP WeblInspect, Network Mapper (NMAP), and/or similar applications.

• Working knowledge of the National Institute of Standards and Technology (NIST) Risk Management Framework (RMF) and ATO processes.

Preferred Qualifications:

• Degree in Computer Science, Cybersecurity, or other cyber discipline.

Security Clearance Requirements:

• Must have a current/active Top Secret clearance with eligibility to obtain SCI.

• Selected candidate may be required to undergo a Polygraph.

Physical Requirements:

• Must be able to remain in a stationary position 50%

• Needs to occasionally move about inside the office to access file cabinets, office machinery, etc.

• Constantly operates a computer and other office productivity machinery, such as a calculator, copy machine and computer printer

• Often positions self to maintain computers in the lab, including under the desks and in the server closet

• Frequently communicates with co-workers, management and customers, which may involve delivering presentations. Must be able to exchange accurate information in these situations

ManTech International Corporation, as well as its subsidiaries proactively fulfills its role as an equal opportunity employer. We do not discriminate against any employee or applicant for employment. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, disability, or status as a protected veteran.

If you are a qualified individual with a disability and require a reasonable accommodation to apply for a position with ManTech through its online applicant system, please email us at and provide your name and contact information.