Senior DHS ISSE: RMF/ATO Security Engineer (TS/SCI)

onezerollc; Washington (District of Columbia); On-site; USD 180,000 - 240,000; Full time

Benefits offered by this job

Parking stipend

Job summary

OneZero Solutions, LLC is seeking a DHS Information Systems Security Engineer Senior to lead the design, implementation, and testing of security controls for DHS systems and networks. The role requires TS/SCI clearance and prior DoD/Federal government ISSE experience.

You will conduct security assessments, configure security appliances, develop secure architectures, and collaborate with DHS teams to maintain ATO readiness while mentoring junior ISSO staff.

Qualifications

• 12+ years of ISSE experience in DoD/Federal Government.
• Experience with security frameworks and RMF/DSA integration.
• Strong knowledge of network security, cryptography, vulnerability management, and incident response.

Responsibilities

• Lead the design, implementation, and testing of security controls for DHS systems and networks.
• Conduct comprehensive security assessments and penetration testing; identify vulnerabilities and mitigations.
• Configure and manage security appliances, firewalls, IDS/IPS, VPNs, encryption, and SIEMs.
• Develop and maintain secure network architectures and system configurations.
• Collaborate with system owners and developers to integrate security controls.
• Stay current with threats and best practices; refine security methodologies.
• Mentor junior ISSO staff and work with DHS teams on incidents.

Skills

ISSE experience

DoD/Federal govt

Network security

Penetration testing

RMF/NIST/FISMA

OpenRMF

SIEM

Communication

Independence/teamwork

Education

Bachelor's degree

CRISC

CISSP

Tools

OpenRMF

Job description

OneZero Solutions, LLC is seeking a DHS Information Systems Security Engineer Senior to lead the design, implementation, and testing of security controls for DHS systems and networks. The role requires TS/SCI clearance and prior DoD/Federal government ISSE experience.

You will conduct security assessments, configure security appliances, develop secure architectures, and collaborate with DHS teams to maintain ATO readiness while mentoring junior ISSO staff.