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Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md). --- # Security Engineer - Arlington, VA - **Company:** Serco - **Location:** Arlington, VA, United States - **Experience:** Expert - **Contract:** Contract - **Skills:** Microsoft Windows, Amazon Web Services, Amazon Elastic Compute Cloud, Amazon S3, JIRA, Audit Trail, Bash Shell, Cloud Computing, Cloud Computing Security, CompTIA Security+, Cyber Security, Computer Programming, System Configuration, Data Cleansing, Linux, Event Logging, Github, Identity and Access Management, Intrusion Detection and Prevention, JSON, Python (Programming Language), Log Analysis, Windows PowerShell, Kusto Query Language, Service Pack, Security Information and Event Management, Systems Integration, Software Vulnerability Management, Computer Networking Systems, Cloud Platform System, Mitre Att&ck, Cyber Threat Analysis, Amazon Virtual Private Cloud (VPC), Gitlab, Git, Kubernetes, Information Technology, Cybercrime, Nessus, Cloudwatch, Restful APIs, Decoding, Cyber Warfare, Software Version Control, Security Orchestration, Automation & Response, Servicenow, Vulnerability Analysis - **Published:** November 13, 2026 - **Apply:** https://dejobs.org/x/x/007881FA71FD44CDB69BA5AC2542B461/job/ ## About the Role * An interim or active DoD Secret security clearance. * U.S. Citizenship. * Bachelor's degree in Computer Science, Cybersecurity, or a related technical field. * 5 years of cybersecurity engineering, cyber operations, information security experience, or related experience. * An active CompTIA Security+ CE certification or equivalent DoD 8140/8570 baseline certification. * Demonstrated hands-on experience administering, securing, and troubleshooting Linux, Windows, enterprise networking, and cloud-based infrastructures. * Proven experience applying the Army RMF process, NIST cybersecurity standards (SP 800-53), DISA STIGs, and vulnerability management tools (ACAS/Nessus) from an engineering implementation and technical risk analysis perspective-developing practical remediation solutions and automating security checks. Additional desired qualifications: * Ability to write operational scripts from scratch (Python, PowerShell, or Bash). Modifying existing scripts or relying solely on GUI tools is insufficient. * Proven ability to manually analyze PCAPs, Windows Event Logs, Linux audit logs, and AWS CloudTrail data to reconstruct security events. * Ability to troubleshoot broken applications or services after applying DISA STIGs or security patches without simply disabling security controls, * Hands-on experience supporting and securing cloud architectures, specifically within AWS environments (EC2, VPC, IAM, S3, CloudWatch, GuardDuty). * Experience integrating security into the Software Development Life Cycle (SDLC), using version control software (Git, GitHub/GitLab), and managing technical workflows in ticket-tracking systems (Jira, ServiceNow). * Technical experience deploying, configuring, and sustaining ACAS and AESS (HBSS/Trellix) across enterprise enclaves to support A&A and continuous monitoring processes. * Knowledge of Army PPB BOS (Planning, Programming, Budgeting, and Execution Business Operating System) financial processes and experience collaborating with Army stakeholders, Authorizing Officials (AOs), and Security Control Assessors (SCAs). ## Description Serco is seeking a Security Engineer to support the Army PPB BOS program. In this role, you will serve as a hands-on cybersecurity professional responsible for protecting mission-critical Army systems and infrastructure. You will apply your expertise across security operations, threat hunting, system hardening, vulnerability remediation, cloud security, and security automation to strengthen the cyber defense posture of critical Army mission systems. This position is primarily focused on hands-on cybersecurity engineering and operations. Successful candidates will have direct experience implementing, operating, troubleshooting, and improving cybersecurity technologies and controls. While familiarity with RMF documentation, compliance processes, and assessment activities is valuable, the primary focus of this role is technical execution, security engineering, threat detection, incident response, and system defense. Serco supports the U.S. Army through the Planning, Programming, Budgeting, and Execution Business Operating System (PPB BOS) program. Our team delivers mission-focused technology and cybersecurity solutions that help maintain secure, resilient, and compliant systems supporting Army operations and decision-making. Candidates must possess an interim or active DoD Secret security clearance. Additionally, candidates must reside within the Washington, DC, Maryland, or Virginia (DMV) area and be willing to work onsite at the Pentagon up to 80% of the time. In this role, you will: * Lead the design, implementation, hardening, and sustainment of cybersecurity capabilities across Linux, Windows, enterprise networks, and cloud-based infrastructures (AWS). * Partner directly with system administrators, software developers, engineers, and government customers to translate technical risk analysis into practical, hands-on remediation and architecture improvements. * Actively triage and contain threats using EDR/endpoint protection platforms (e.g., CrowdStrike, Microsoft Defender, Trellix/AESS/HBSS). Analyze process trees, decode malicious payloads (e.g., encoded PowerShell), and isolate compromised endpoints directly from the console. * Write custom SIEM queries (KQL or SPL) from scratch to hunt for advanced persistent threats mapped to the MITRE ATT&CK framework. Pivot through raw network, host, and cloud logs without relying on pre-built dashboards or natural language generators. * Go beyond simply running ACAS/Nessus scans and tracking POA&Ms. Perform technical risk analysis and work alongside engineering teams to apply patches, enforce DISA STIGs, configure Group Policy Objects (GPOs), and modify system configurations across Windows and Linux hosts. * Build and maintain custom Python, Bash, or PowerShell scripts to automate incident triage, STIG/control validation, data enrichment, and containment actions. Interact with REST APIs, handle pagination, parse JSON output, and integrate security checks into CI/CD pipelines. * Implement and enforce technical security controls within AWS and containerized/Kubernetes environments, including IAM least-privilege policies, VPC security groups, GuardDuty/CloudTrail log analysis, and container vulnerability scanning.