> Markdown version of [/jobs/ext/4581397-senior-systems-security-engineer-isse-isso-support](https://www.wearedevelopers.com/jobs/ext/4581397-senior-systems-security-engineer-isse-isso-support). Every page supports `.md` or `Accept: text/markdown`. Links point to the HTML versions so they work for humans too. Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md). --- # Senior Systems Security Engineer (ISSE / ISSO Support) - **Company:** TEKSYSTEMS INC. - **Location:** King George, VA, United States - **Experience:** Expert - **Salary:** $104,000 - $141,440 - **Contract:** Contract - **Skills:** Cyber Security, Information Systems, Identity and Access Management, Public Key Infrastructure, Software Vulnerability Management, SC Clearance - **Published:** November 5, 2026 - **Apply:** https://www.clearancejobs.com/jobs/9293812/senior-systems-security-engineer-isse-isso-support ## About the Role Active Secret Clearance or Active Interim Secret Clearance. DoD IAM Level II Certification (CAP, CASP+, CISM, GSLC, or equivalent). 3+ years of experience supporting RMF, A&A, and ATO activities. Experience building Accreditation & Authorization (A&A) packages from start to finish. Experience supporting cybersecurity compliance within DoD or federal government environments. Strong understanding of RMF processes, security controls, and accreditation requirements. Excellent written and verbal communication skills. Ability to work effectively with technical teams and government stakeholders., eMASS experience. ISSO or ISSE experience. Knowledge of Public Key Infrastructure (PKI). Experience with DoD Ports, Protocols, and Services (PPS). Familiarity with DoD Information Assurance Vulnerability Management (IAVM) requirements. Experience supporting classified network environments. Strong understanding of government cybersecurity compliance frameworks. ## Description TEKsystems is seeking a Senior Systems Security Engineer to support a mission-critical Department of Defense cybersecurity program in Dahlgren, VA. This position will focus on Risk Management Framework (RMF), Assessment & Authorization (A&A), and Authority to Operate (ATO) efforts for both classified and unclassified government systems. The ideal candidate will have experience building accreditation packages from start to finish, working directly with government stakeholders, and ensuring systems remain compliant with DoD cybersecurity requirements throughout the authorization lifecycle. Responsibilities Support Information Systems Security Officer (ISSO) functions for government information systems. Develop, maintain, and update RMF documentation and accreditation packages. Lead Assessment & Authorization (A&A) efforts and support Authority to Operate (ATO) activities. Review and maintain Certification & Accreditation (C&A) documentation. Develop and maintain security documentation including CONOPS, SOPs, Disaster Recovery Plans, and Emergency Action Plans. Coordinate with ISSMs, IAOs, IAMs, Program Managers, and cybersecurity teams regarding system compliance and authorization activities. Support vulnerability management and security compliance initiatives. Review security controls and ensure compliance with DoD cybersecurity standards and policies. Maintain security records, inventories, and accreditation documentation. Assist with firewall reviews, security policy implementation, and ongoing compliance efforts. Support recurring ATO renewals and ongoing RMF package maintenance.