Information Systems Security Engineer (ISSE) - Top Secret Clearance Required

TEKsystems•Richardson, TX

3d•$75 - $85•Onsite

About The Position

We are seeking an Information Systems Security Engineer (ISSE) to serve as the cybersecurity authority for our infrastructure program, ensuring all systems are designed, deployed, and operated in full compliance with DoD security requirements. You will own the security engineering lifecycle from initial architecture through ATO and into continuous monitoring — working across the infrastructure, network, and systems engineering teams to embed security at every layer of the environment. This is a senior, high-visibility role with direct engagement with government security stakeholders and program leadership.

Requirements

8–10+ years of hands-on experience in information systems security engineering in DoD or cleared defense contractor environments
Deep expertise in the RMF process including ATO package development and direct engagement with government authorizing officials
Strong working knowledge of NIST 800-53, DISA STIGs, CNSSI 1253, and ICD 503 security frameworks
Experience designing and implementing SIEM solutions and security monitoring architectures in classified environments
Demonstrated experience leading vulnerability management programs including scanning tools such as Nessus, ACAS, or equivalent
Broad technical understanding of infrastructure security across virtualization, networking, operating systems, and identity management layers
Active Top Secret security clearance required; TS/SCI eligibility strongly preferred

Nice To Haves

Experience supporting programs at the TS/SCI level
Familiarity with cloud security frameworks and hybrid environment security architectures
Experience with security automation, SOAR platforms, or scripting for security operations
Knowledge of cross-domain solutions (CDS) and data transfer requirements in classified environments
Familiarity with JSIG, ICD 503, or IC-specific security requirements
Bachelor's degree in Cybersecurity, Computer Science, Information Technology, or a related field; equivalent experience considered
DoD 8570/8140 IAT Level III or IASAE Level II or III certification (CISSP, CASP+, or equivalent)

Responsibilities

Lead security engineering activities across the program, ensuring all infrastructure components are designed and implemented in accordance with DoD, DISA, and NIST security requirements
Own the RMF process end-to-end, including system categorization, security control selection, implementation, assessment, and ATO package development and submission
Develop and maintain all required RMF documentation including System Security Plans (SSPs), Security Assessment Reports (SARs), Plans of Action and Milestones (POA&Ms), and Risk Assessment Reports
Lead STIG implementation and compliance activities across all infrastructure layers including servers, hypervisors, network devices, operating systems, and applications
Design, deploy, and manage SIEM solutions for log aggregation, correlation, and security event monitoring across classified and unclassified environments
Conduct and oversee vulnerability management activities including recurring scans, findings analysis, remediation tracking, and reporting
Serve as the primary security liaison with government Authorizing Officials (AOs), ISSOs, and security control assessors
Provide security engineering guidance to infrastructure, network, and systems engineering teams throughout the design and build phases of the program
Develop and enforce security policies, procedures, and configuration baselines aligned with DISA STIGs and NIST 800-53 controls
Support incident response activities including detection, containment, analysis, and reporting in coordination with government security teams
Maintain continuous monitoring programs and ensure ongoing compliance with ATO conditions and security control requirements