Information Systems Security Engineer (ISSE)

CACI; Sterling (IL); On-site; USD 121,000 - 266,000; Full time

Job summary

CACI is seeking an Information Systems Security Engineer (ISSE) to strengthen the security posture of our network infrastructure. You will implement and maintain security measures across the system lifecycle, from design through operation, ensuring robust defenses against emerging threats.

The role focuses on secure architecture, RMF and A&A activities, and documentation such as SSP/SCTM/BoE, with emphasis on Zero Trust and SDN integrations for continuous verification.

Qualifications

• Bachelor’s degree in CS, cybersecurity, IT, or related field, or equivalent experience.
• 10+ years of ISSE/ISSO experience, preferably DoD/IC.
• Current TS/SCI with Polygraph clearance required.
• DoD 8570/8140 IASAE Level II certs (CISSP, CASP+, CSSLP).
• Knowledge of NIST 800-53 controls and RMF processes.
• Experience with RMF, A&A documentation and security documentation.
• Experience with Nessus/ACAS, SCAP and basic network security concepts.
• Strong written and verbal communication, analytical thinking.

Responsibilities

• Design and document secure system architectures meeting mission requirements.
• Support RMF activities from categorization to ATO.
• Develop and maintain SSP, SCTM, and BoE documentation.
• Define system security requirements and integrate zero trust / SDN controls.
• Evaluate designs for security impacts before implementation.
• Ensure compliance with NIST SP 800-53, ICD 503, CNSSI 1253.
• Implement ConMon activities and track system health/compliance.
• Perform risk assessments, security audits, and remediate findings.
• Assist with incident response and on-call rotations.
• Support network mapping and data flow across the enterprise.

Skills

Analytical skills

Problem solving

Communication

Education

Bachelor’s degree in Computer Science, Cybersecurity, Information Technology, or related field, or equivalent experience

Tools

Xacta

eMASS

Nessus (ACAS)

SCAP

Job description

Job Title: Information Systems Security Engineer (ISSE)

Job Category: Information Technology

Time Type: Full time

Minimum Clearance Required to Start: TS/SCI with Polygraph

Employee Type: Regular

Percentage of Travel Required: Up to 10%

Type of Travel: Local

* * *

The Opportunity:

We are seeking a technically proficient Information Systems Security Engineer to support the security posture of our Network Infrastructure. In this role, you will implement and maintain comprehensive security measures to protect customer data, systems, and networks. This position plays an important role in ensuring security is integrated throughout the system lifecycle, from design through operation, supporting the mission while maintaining strong defensive measures.

Responsibilities:

• Security Architecture Support: Contribute to the design and documentation of secure system architectures that meet mission requirements and security standards.
• RMF Process Execution: Support Risk Management Framework (RMF) activities (Steps 1–6), assisting Information System Security Officers (ISSOs) in taking systems from initial categorization through Authorization to Operate (ATO).
• Security Documentation: Develop and maintain Assessment & Authorization (A&A) documentation, including Systems Security Plans (SSP), Security Control Traceability Matrix (SCTM), and Body of Evidence (BoE).
• Security Engineering: Designs security architectures from requirements phase, defining system security requirements, and integrating capabilities including Zero Trust Architecture Software Defined Networking (SDN), macro/micro-segmentation, and software-defined perimeter controls to enable continuous verification and minimize network attack surfaces.
• Security Evaluation: Participate in formal and informal design reviews to identify potential security weaknesses, deficiencies, and/or vulnerabilities in the design - evaluating designs for security impacts before implementation.
• Compliance Implementation: Ensure hardware and software comply with Government Security Certification Officer (SCO) requirements and align with NIST SP 800-53, ICD 503, and CNSSI 1253 standards.
• Continuous Monitoring: Implement and maintain continuous monitoring (ConMon) activities using automated tools to track system health and compliance status.
• Vulnerability Management: Perform risk assessments and security audits; use tools like Nessus (ACAS) and SCAP to identify, track, and remediate vulnerabilities.
• Incident Response Support: Assist with incident response activities and participate in on-call rotation for security incidents.
• Network Integration Support: Provide support for network mapping activities and system interdependencies to ensure secure data flow across the enterprise.

Qualifications:

Required:

• Education: Bachelor’s degree in Computer Science, Cybersecurity, Information Technology, or a related field, or equivalent experience.
• Experience: 10+ years of related work experience with demonstrated ISSE/ISSO responsibilities, preferably within the Intelligence Community or DoD environment.
• Clearance: Current TS/SCI with Polygraph (Required).
• Certifications: Must meet DoD 8570/8140 IASAE Level II requirements (e.g., CISSP, CASP+, or CSSLP).
• Compliance Knowledge: Working knowledge of NIST 800-53 security controls and experience with RMF processes.
• Technical Skills: Understanding of network protocols (TCP/IP, DNS, HTTP) and security concepts including VPNs, IDS/IPS, and DMZ configurations.
• Tooling Experience: Experience with A&A tracking tools such as Xacta or eMASS.
• Communication: Strong analytical, problem-solving, and communication skills with the ability to document technical security findings clearly.

Desired:

• Security Certifications: CISM, Security+, CCSP, or GSLC.
• Networking Certifications: CCNP Enterprise with the SD WAN, CCIE Security, JNCIS-ENT, JNCIP-ENT, or JNCIE-ENT
• Platform Experience: Exposure to major firewall platforms (e.g., Palo Alto, Cisco ASA, Fortinet).
• Tools Experience: Cisco Identity Services Engine (ISE), Juniper Contrail, Cisco DevNet, Juniper Automation, or other networking orchestration tool.
• Scripting: Basic proficiency in Ansible, Python, PowerShell, or Bash for task automation.
• SIEM Experience

This position is contingent on funding and may not be filled immediately. However, this position is representative of positions within CACI that are consistently available. Individuals who apply may also be considered for other positions at CACI.

What You Can Expect:

A culture of integrity.

At CACI, we place character and innovation at the center of everything we do. As a valued team member, you’ll be part of a high-performing group dedicated to our customer’s missions and driven by a higher purpose – to ensure the safety of our nation.

An environment of trust.

CACI values the unique contributions that every employee brings to our company and our customers - every day. You’ll have the autonomy to take the time you need through a unique flexible time off benefit and have access to robust learning resources to make your ambitions a reality.

A focus on continuous growth.

Together, we will advance our nation’s most critical missions, build on our lengthy track record of business success, and find opportunities to break new ground — in your career and in our legacy.

Pay Range

There are a host of factors that can influence final salary including, but not limited to, geographic location, Federal Government contract labor categories and contract wage rates, relevant prior work experience, specific skills and competencies, education, and certifications. Our employees value the flexibility at CACI that allows them to balance quality work and their personal lives. We offer competitive compensation, benefits and learning and development opportunities. Our broad and competitive mix of benefits options is designed to support and protect employees and their families. At CACI, you will receive comprehensive benefits such as; healthcare, wellness, financial, retirement, family support, continuing education, and time off benefits.

The proposed salary range for this position is:

$120,800 - $265,800

CACI is anEqualOpportunity Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, pregnancy, sexual orientation, age, national origin, disability, status as a protected veteran, or any otherprotectedcharacteristic.