Senior Endpoint Security Systems Engineer

Senior Endpoint Security Systems Engineer
Adelphi, MD (Hybrid 3 days onsite) | Full-Time | Active TS/SCI Required

Our client seeking a Senior Endpoint Security Systems Engineer to support the C5ISR Center Cyber Security Service Provider (CSSP) program. In this role, you'll lead the engineering, deployment, and sustainment of enterprise host-based defense capabilities across mission assets, with a primary focus on our Trellix environment (ePolicy Orchestrator and Endpoint Security suite) and a secondary focus on operationalizing Elastic Defend for Endpoint as part of a multi-tiered defense architecture. You'll work closely with mission system owners, infrastructure architects, and defensive cyber operations teams to protect Windows, Linux, and macOS platforms across on-premises environments and cloud IaaS.







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What You'll Do

• Administer, upgrade, and harden central endpoint management consoles (primarily Trellix ePO) across multi-tier networks, isolated enclaves, and cloud-connected management VPCs
• Engineer and sustain the Trellix suite alongside Elastic Agent/Elastic Defend, managing agent lifecycle, compatibility, and synchronized host-level protection
• Direct endpoint and server integration across on-premises and cloud IaaS instances (Windows, Linux, macOS)
• Design, benchmark, and deploy scan exclusion policies, behavioral rules, DLP rules, and content updates that protect hosts without degrading performance
• Troubleshoot agent connectivity, registration, and communication failures across hybrid network boundaries; resolve product installation and deployment issues
• Partner with mission owners to engineer precise exclusions and resolve application conflicts caused by security policies
• Investigate and correct ePO console misconfigurations, policy inheritance errors, and database issues
• Maintain compliance with DISA STIGs, OPORD, and endpoint security requirements, supporting continuous monitoring reporting
• Collaborate with CSSP threat detection and hunt teams to implement custom endpoint signatures, IOCs, and automated containment policies

Required Qualifications

• Active Top Secret/SCI clearance (U.S. citizenship required); Secret active to start acceptable
• Bachelor's degree in Cybersecurity, Computer Science, or a related STEM/IT field with 8+ years of relevant systems engineering/endpoint security experience, OR a Master's degree with 6+ years
• DoD 8140 compliance upon start: an active certification meeting CSSP-Infrastructure Support, CSSP-Analyst, or IAT Level II/III requirements (e.g., CEH, CySA+, GCIH, GCFA, GMON, CISSP, CASP+, or CISM)
• Hands-on experience administering and upgrading Trellix ePolicy Orchestrator (ePO), Trellix Agent, and core modules including Endpoint Security (Threat Prevention and Firewall), Data Loss Prevention (DLP), and Policy Auditor
• Proven experience deploying and maintaining endpoint security agents across enterprise Linux (RHEL/CentOS/Rocky), Windows (Server and Desktop), and macOS environments
• Practical experience managing and troubleshooting host-based security across on-premises and cloud IaaS (VM) instances
• Strong troubleshooting skills for OS performance impacts, resource contention, and agent-server communication across complex network topologies

Preferred Qualifications

• Experience with Trellix Solidcore (Application Control) for application whitelisting and file integrity monitoring (FIM)
• Hands-on experience deploying, configuring, and tuning Elastic Agent and Elastic Defend for Endpoint
• Familiarity with macOS enterprise security configurations and deployment tools (Apple MDM, JAMF Pro)
• Experience integrating or reporting endpoint security posture into DISA COAMS and CMRS
• Familiarity with cloud networking, auto-scaling, and security groups in AWS, Azure, or GCP
• Scripting ability in PowerShell, Bash, or Python for automating agent installation, verification, and health monitoring
• Working knowledge of the MITRE ATT&CK framework and its application to host-based detections
  
  
  
  
  
  
  
  

Delta System & Software, Inc. is an Equal Opportunity Employer. We celebrate diversity and are committed to creating an inclusive environment for all employees. All employment decisions are based on business needs, job requirements, and individual qualifications. We recruit, hire, employ, train, promote, and compensate individuals based on job-related qualifications and abilities. Delta also has a longstanding policy of providing a work environment that respects the dignity and worth of each individual and is free from all forms of employment discrimination, including harassment, because of race, color, sex, gender, age, religion or religious creed, national origin, ancestry, citizenship, marital status, sexual orientation, gender identity, gender expression, genetic information, physical or mental disability, military or veteran status, or any other characteristic protected by law.