Information System Security Engineer (ISSE)

TEKsystems is seeking an Information Systems Security Engineer (ISSE) with a Top Secret Clearance in Richardson, TX in support of a Secure Development Environment (SDE) Infrastructure Deployment to support classified and controlled engineering workloads associated with Department of Defense (DoD) programs., This project is projected to be 12 months in duration and will include a one time 30 day CONUS travel assignment for a deployment., 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.

What You’ll Do -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

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, 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)