Endpoint Security Engineer (EDR/XDR) (Hybrid)

Endpoint Security Engineer Tier One Technologies has an immediate need for an Endpoint Security Engineer for our US Government client. This hybrid Contract-to-Hire position will be available to start in Falls Church, VA, Morrisville, NC or Eagan, MN. SELECTED CANDIDATES WITHOUT REQUIRED CLEARANCE WILL BE SUBJECT TO A FEDERAL GOVERNMENT BACKGROUND INVESTIGATION TO RECEIVE IT. Responsibilities Design, deploy, and operationalize active, behavior-based endpoint detection and response (EDR/XDR) capabilities across the client's network. Balance proactive protection with business continuity - partnering directly with end-users and application owners to tune policies and eliminate operational friction, while providing tier-3/tier-4 technical escalations to Security Operations Center (SOC) analysts and IT Operations staff during active investigations. Fleet-Wide Behavioral Defense & Control Engineering: Engineer, deploy, and maintain Next-Gen Antivirus (NGAV) and Endpoint Detection & Response (EDR/XDR) agents (e.g., CrowdStrike Falcon, Microsoft Defender for Endpoint, SentinelOne) across hundreds of thousands of heterogeneous endpoints. Implement active behavioral protections against zero-day malware, living-off-the-land binaries (LotLBs), fileless execution, and credential dumping. Application Owner & End-User Engagement (Business Impact Management): Serve as the primary technical partner to application owners and business units, establishing baseline behavior profiles to minimize false positives, performance degradation, or operational downtime across critical retail, logistics, and supply chain applications. Manage allowlisting, exception workflows, and phased ring deployments (canary/pilot/production) to ensure silent, high-efficacy protection without disrupting day-to-day warehouse or logistics operations. SOC & IT Operations Event Investigation Support: Act as endpoint security escalation lead for SOC analysts during high-severity threat detection and response events. Act as endpoint operations escalation lead for IT administrators during high-impact event investigation and remediation efforts. Perform advanced host forensics, process-tree reconstruction, memory analysis, and script-based live remediation (e.g., host isolation, automated artifact collection, registry rollbacks). Hybrid & Multi-Cloud Workload Protection: Extend endpoint security standards across private data center virtualization layers (VMware/Nutanix) and ephemeral multi-cloud infrastructure (EC2, Azure VMs, Compute Engine, containerized hosts). Control Efficacy & Continuous Validation: Continuously measure and test security control efficacy using automated attack simulation (BAS) tools and Purple Team exercises. Track and report on agent health, tamper-resistance, telemetry pipeline integrity, and coverage metrics aligned with enterprise asset management systems. Qualifications Bachelor's or Master's degree in Computer Science, Information Security or related field. If an individual's degree is not in the applicable field, then 4 additional years of related experience is required. 7+ years of progressive experience in technical Cybersecurity engineering or infrastructure security roles. 3+ years of directly engineering and administering enterprise-grade EDR/XDR platforms across 50,000+ endpoints in a distributed hybrid environment. Expert-level proficiency administering enterprise-scale endpoint platforms across Windows, macOS, Linux distributions, and container runtime environments. Deep mastery of process lineage, behavioral IOAs (Indicators of Attack), Sysmon telemetry, and detection authoring using query languages such as SQL, KQL (Kusto Query Language), Splunk SPL, or YARA. Demonstrated track record supporting active SOC investigations and collaborating cross-functionally with system owners in large-scale enterprise environments. Deep understanding of Windows/Linux kernel architectures, API hooking, hypervisor isolation, and multi-cloud workload identity integrations. Strong programming/scripting abilities in PowerShell, Python, or Bash to orchestrate fleet-wide remediations and automate policy compliance at scale. Fluency applying appropriate AI/ML technologies and analytics platforms (Splunk, Databricks, Elastic) to streamline and/or automate activities including but not limited to research, developing documentation, and supporting development of executive communications. Fluency applying appropriate AI/ML technologies to automate security activities to improve timeliness or full automation of event response activities. Proven ability to balance stringent security controls with business operational velocity, ensuring minimal disruption to end-user productivity and mission-critical COTS/proprietary software. Capability of methodically triaging active enterprise threats under pressure and articulating complex host-based attacks to executive leadership. To have a mindset geared toward "Infrastructure-as-Code" and policy automation rather than manual device-by-device intervention. Preferred Certifications: GIAC Certified Enterprise Defender (GCED) or GIAC Certified Incident Handler (GCIH), or GCFA (Forensic Analyst) or CISSP (Certified Information Systems Security Professional). Specialized Vendor Engineering Credentials (e.g., CrowdStrike Certified Falcon Administrator/Hunter, Microsoft Certified: Security Operations Analyst Associate / SC-200) a PLUS. Excellent communication skills. Must be a US Citizen or Permanent US Resident (Green Card Holder). Must be able to obtain Public Trust Clearance. Be able to pass a drug screening, criminal history, and credit checks. Must have lived in the United States for the past 5 years. Cannot have more than 6 months travel outside the United States within the last five years. Military Service excluded. (Exception does not include military family members.) A.C.Coy Company