Senior Information Systems Security Engineer (ISSE)

Location: Annapolis Junction, MD Security Clearance: Active TS/SCI [Required] Job Type: Full-Time Target Salary Range*:$150,000 - $210,000 This represents the potential salary range for this position depending on education level, years of experience and/or certifications in addition to other position specific requirements which may impact salary Position Overview The Senior Information Systems Security Engineer designs, implements, and maintains enterprise security architecture aligned with NIST RMF, DoD STIGs, CIS benchmarks, and organizational cybersecurity policies. This role performs security engineering across the system development lifecycle, supports vulnerability management, integrates cybersecurity requirements across enterprise environments, and ensures development and operational systems are functional and secure. Key Responsibilities Security Architecture and Engineering Design, implement, and maintain enterprise security architecture aligned with NIST RMF, DoD STIGs, CIS benchmarks, and organizational cybersecurity policies.Perform security engineering activities across the system development lifecycle, including requirements analysis, system design reviews, security testing, and accreditation support.Integrate cybersecurity requirements into Windows and Linux server environments, cloud infrastructure, virtualization platforms, and containerized applications.Responsible for the design, development, implementation, and integration of DoD IA architectures, systems, or system components for use within computing, network, and enclave environments.Ensure the architecture and design of development and operational systems are functional and secure.Support designs for program of record systems and special purpose processing nodes with platform IT interconnectivity. Vulnerability Management and Compliance Implement vulnerability management processes using Tenable Nessus, ACAS, and Qualys to identify, assess, and remediate system vulnerabilities.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.Determine security requirements by evaluating business strategies and requirements, researching information security standards, conducting system security and vulnerability analyses and risk assessments, studying architecture and platforms, identifying integration issues, and preparing cost estimates.Establish a framework by which cyber risk can be measured and quantified in the marketplace. Security Monitoring, Incident Response, and Threat Detection Support incident response and forensic investigations by analyzing security logs, SIEM alerts, network traffic, and endpoint telemetry using Splunk Enterprise.Monitor, analyze, and detect cyber events and incidents within information systems and networks under general supervision.Assist with integrated, dynamic cyber defense.Coordinate and maintain security toolsets to support continuous monitoring and ongoing authorization programs.Evaluate and implement cybersecurity tools and technologies to improve system security posture, continuous monitoring, and threat detection capabilities. Security Tools, Automation, and Endpoint Protection Develop automation scripts using PowerShell, Bash, and Python to streamline vulnerability remediation, account auditing, compliance reporting, and security monitoring tasks.Engineer endpoint protection and hardening solutions using Trellix ePO On-Prem, host-based firewalls, and application whitelisting technologies.Implement security systems by specifying intrusion detection methodologies and equipment, directing equipment and software installation and calibration, preparing preventive and reactive measures, creating, transmitting, and maintaining keys, providing technical support, and completing documentation.Verify security systems by developing and implementing test scripts.Administer, configure, and troubleshoot CyberArk core modules, including Enterprise Password Vault, Password Vault Web Access, Central Policy Manager, and Privileged Session Manager. Documentation, Training, and Technical Leadership Produce technical security documentation, architecture diagrams, standard operating procedures, and executive-level risk assessment reports.Maintain security by monitoring and ensuring compliance with standards, policies, and procedures.Conduct incident response analyses.Develop and conduct training programs.Present technical briefings to leadership. Qualifications Experience Strong background in networking, including TCP/IP, firewalls, and VPNs.Strong background in cloud security, including AWS and Azure.Strong background in Kubernetes and DevSecOps.Deep understanding of NIST SP 800-161, NIST RMF, FedRAMP, Common Criteria, ATO package development, and cybersecurity compliance, including 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 Linux.Experience with scripting and automation using PowerShell, Python, Bash, and Ansible.Proven experience leading projects and mentoring junior ISSEs. Skills Ability to design, implement, and maintain enterprise security architecture.Ability to perform security engineering across the system development lifecycle.Ability to integrate cybersecurity requirements across server, cloud, virtualization, and containerized environments.Ability to perform security impact analysis for system changes, software deployments, and infrastructure upgrades.Ability to produce technical security documentation, architecture diagrams, standard operating procedures, and executive-level risk assessment reports.Ability to present technical briefings to leadership. Certifications DoD 8570.1-M / DoD 8140 IAT Level III certification, such as SecurityX, GCIH, CISA, or CISSP. [Required]