Information Systems Security Engineer (ISSE)

ResponsibilitiesPeraton is seeking an Information Systems Security Engineer (ISSE) to support our customer onsite in Washington D.C. Responsibilities include:Design, implement, and maintain enterprise security architectures aligned with NIST RMF, DoD STIGs, CIS benchmarks, and organizational cybersecurity policies.Perform security engineering activities across system development lifecycle (SDLC), including requirements analysis, system design reviews, security testing, and accreditation support.Implement vulnerability management processes utilizing Tenable Nessus, ACAS, and Qualys to identify, assess, and remediate system vulnerabilities.Integrate cybersecurity requirements into Windows and Linux server environments, cloud infrastructure, virtualization platforms, and containerized applications.Support incident response and forensic investigations by analyzing security logs, SIEM alerts, network traffic, and endpoint telemetry using Splunk Enterprise.Develop automation scripts using PowerShell, Bash, and Python to streamline vulnerability remediation, account auditing, compliance reporting, and security monitoring tasks.Collaborate with system administrators, network engineers, ISSOs, and application teams to remediate security findings and implement secure configuration baselines.Perform security impact analysis for system changes, software deployments, and infrastructure upgrades to ensure continued compliance and operational security.Engineer endpoint protection and hardening solutions utilizing Trellix ePO – On-prem, host-based firewalls, and application whitelisting technologies.Evaluate and implemented cybersecurity tools and technologies to improve system security posture, continuous monitoring, and threat detection capabilities.Produce technical security documentation, architecture diagrams, standard operating procedures (SOPs), and executive-level risk assessment reports.Experience administrating, configuring, and troubleshooting core modules such as Enterprise Password Vault (EPV), Password Vault Web Access (PVWA), Central Policy Manager (CPM), and Privileged Session Manager (PSM) in CyberArk.Qualifications5 years with BS/BA; 3 years with MS/MA; 9 years in lieu of a BS degree may be considered.Must possess an active Top Secret with SCI EligibilityStrong background in networking (TCP/IP, firewalls, VPNs), cloud security (AWS/Azure), Kubernetes, and DevSecOps.Deep understanding of NIST SP 800-161, NIST RMF, FedRAMP, Common Criteria, ATO package development, and cybersecurity compliance (STIGs).Hands-on experience managing and deploying Tenable Nessus, CyberArk, Trellix, Splunk Enterprise, VMware vSphere, GitLab, Microsoft Windows Server, Red Hat Enterprise Linux and Ubuntu LinuxExperience with scripting and automation with Powershell, Python, Bash and AnsibleProven experience in leading projects and mentoring junior ISSE's.Present technical briefings to leadership.Must have a current DoD 8570.1-M IAT Level III certification (SecurityX (CASP), GCIH, CISA, CISSP)Peraton OverviewPeraton is a next-generation national security company that drives missions of consequence spanning the globe and extending to the farthest reaches of the galaxy. As the world’s leading mission capability integrator and transformative enterprise IT provider, we deliver trusted, highly differentiated solutions and technologies to protect our nation and allies. Peraton operates at the critical nexus between traditional and nontraditional threats across all domains: land, sea, space, air, and cyberspace. The company serves as a valued partner to essential government agencies and supports every branch of the U.S. armed forces. Each day, our employees do the can’t be done by solving the most daunting challenges facing our customers. Visit peraton.com to learn how we’re keeping people around the world safe and secure.Target Salary Range$104,000 - $166,000. This represents the typical salary range for this position. Salary is determined by various factors, including but not limited to, the scope and responsibilities of the position, the individual’s experience, education, knowledge, skills, and competencies, as well as geographic location and business and contract considerations. Depending on the position, employees may be eligible for overtime, shift differential, and a discretionary bonus in addition to base pay.EEOEEO: Equal opportunity employer, including disability and protected veterans, or other characteristics protected by law.Job SummaryRequisition ID: 2026-167861Position Category: Information TechnologyClearance: Top Secret/SCI