Principal Endpoint Security Systems Engineer

Crows; McLean (VA); On-site; USD 131,000 - 237,000; Full time

Benefits offered by this job

Paid Time Off

11 paid Holidays

401K with 6% company match

Flexible schedules

Education and Training Support

Job summary

Leidos is seeking a Principal Cybersecurity Engineer in the Intel Sector’s Analysis Solutions Business Area. The role focuses on protecting information systems, designing and maintaining security controls, and ensuring compliance with cybersecurity policies and RMF processes.

You will collaborate with ISSEs, ISSMs, software developers, and government stakeholders throughout the DevSecOps lifecycle, leading incident response and vulnerability remediation efforts while staying current with threats

Qualifications

• BS or MS with extensive relevant experience; minimum years in description.
• Active TS/SCI with Polygraph is required for consideration.
• Experience implementing and managing SIEM tools (Splunk or similar).
• Experience with endpoint and network security technologies (IDS/IPS, EDR).
• Experience RMF/ATO processes, vulnerability management, and DevSecOps collaboration.
• Professional cybersecurity certifications (Security+, CISSP, CySA+, CEH, GCIH).

Responsibilities

• Plan, implement, manage, monitor, and upgrade security controls and tools.
• Design, configure, troubleshoot, and maintain security technologies and SIEMs.
• Support incident investigation and remediation; participate in change management.
• Audit systems for policy and secure baseline compliance.
• Collaborate with engineering and operations to embed security in DevSecOps.
• Monitor advisories and threat intelligence; enforce secure configurations.
• Support vulnerability management and remediation with teams.

Skills

SIEM engineering

Security engineering

DevSecOps

Incident response

Risk management

Education

Bachelor's degree + 12+ years

Master's degree + 10+ years

Tools

Splunk

HBSS/Trellix

Carbon Black EDR

Tenable/Nessus

Rapid7

Job description

Principal Cybersecurity Engineer

Bethesda, Maryland, United States (On-Site)

Leidos has a new and exciting opportunity for a Principal Cybersecurity Engineer in our Intel Sector's (IS) Analysis Solutions Business Area (ASBA). Our talented team is at the forefront in Security Engineering, Computer Network Operations (CNO), Mission Software, Analytical Methods and Modeling, Signals Intelligence (SIGINT), and Cryptographic Key Management. At Leidos, we offer competitive benefits, including Paid Time Off, 11 paid Holidays, 401K with a 6% company match and immediate vesting, Flexible Schedules, Discounted Stock Purchase Plans, Technical Upskilling, Education and Training Support, Parental Paid Leave, and much more. Join us and make a difference in National Security!

The Cybersecurity Engineer Master is responsible for protecting the customer's information systems, networks, and infrastructure from cyber threats and vulnerabilities. This role supports the design, implementation, and maintenance of security controls that safeguard mission systems and ensure compliance with applicable cybersecurity policies, standards, and regulatory frameworks.

The Cybersecurity Engineer Master will work closely with Information Systems Security Engineers (ISSEs), Information Systems Security Managers (ISSMs), software developers, systems engineers, and government stakeholders throughout the DevSecOps lifecycle. The candidate will perform a full spectrum of cybersecurity engineering activities, including implementing security technologies, supporting incident response efforts, and ensuring systems meet required security and compliance standards.

Primary Responsibilities:

• Plan, implement, manage, monitor, and upgrade security controls and tools used to protect enterprise systems and networks, while identifying opportunities to automate repeatable operations tasks.
• Design, configure, implement, troubleshoot, and maintain security technologies such as firewalls (security groups), endpoint protection tools (HBSS/Trellix, Carbon Black EDR), SIEM platforms (Splunk). Monitor system and network security using Security Information and Event Management (SIEM) tools such as Splunk Enterprise Security to detect, analyze, and respond to potential threats or anomalous activity.
• Support the investigation and remediation of cybersecurity incidents, including system or network breaches and malware infections. Participate in change management processes to ensure system changes maintain security compliance and do not introduce new vulnerabilities.
• Audit systems and configurations to ensure compliance with established cybersecurity policies, standards, and secure configuration baselines.
• Collaborate with engineering, development, and operations teams to integrate security controls into DevSecOps pipelines and system architectures.
• Continuously monitor security advisories, bulletins, and industry threat intelligence to stay informed of current vulnerabilities, threats, and trends. Assist with the implementation and enforcement of secure system configurations and cybersecurity compliance requirements.
• Support vulnerability management activities by reviewing scan results, assessing risk, and coordinating remediation efforts with system owners and technical teams.

Basic Qualifications:

• BS degree and 12 or more years of prior relevant experience, or MS degree and 10 or more years of prior relevant experience. Additional years of experience may be substituted in lieu of a degree.
• Must have an active TS/SCI with a Polygraph, to be considered.
• Experience implementing and managing Security Information and Event Management (SIEM) tools such as Splunk or similar platforms. Experience working with endpoint and network security technologies, including IDS/IPS, HBSS/Trellix or Carbon Black EDR, and related defensive security tools.
• Experience reviewing and analyzing cybersecurity event logs to identify indicators of compromise or suspicious activity. Experience supporting incident response plans, vulnerability management programs, risk management plans, and Plans of Action and Milestones (POA&Ms).
• Experience conducting or supporting technical cybersecurity assessments and security audits. Experience identifying system vulnerabilities and instances of non-compliance with cybersecurity standards and regulatory requirements. Experience collaborating with DevSecOps teams to review vulnerability scan results and support remediation of findings.
• Experience supporting the Risk Management Framework (RMF) authorization process by reviewing security documentation and providing risk-based recommendations to stakeholders regarding system risk posture as part of Authority to Operate (ATO) activities. Manage and track Plans of Action and Milestones (POA&Ms) for customer-sponsored systems, coordinating with key stakeholders including ISSOs, ISSEs, ISSMs, and Security Control Assessors (SCAs)
• Experience applying system security engineering principles in areas such as system security design, lifecycle engineering, authentication and authorization mechanisms, cryptography, intrusion detection, contingency planning, incident handling, auditing, configuration management, and change control.
• Professional cybersecurity certifications such as Security+, CISSP, CySA+, CEH, or GCIH.

Preferred Qualifications:

• Experience with cybersecurity tools such as Rapid7, Tenable/Nessus, SonarQube, Fortify, Chainguard, or endpoint detection and response (EDR) platforms, as well as using STIG viewers and compliance tools to assess systems against established security configuration baselines.
• Experience implementing and managing network and application firewalls, incident detection platforms, and digital forensic tools.
• Experience with automation tools such as Ansible or CloudFormation to support infrastructure and security automation. Experience with Agile software development environments and scripting/programming languages such as Python or PowerShell. (e.g., React).
• Familiarity with cloud computing environments, including AWS, Oracle Cloud, or Google Cloud Platform (GCP).
• Experience with system monitoring and health tools such as SolarWinds.
• Experience working with DevSecOps pipelines and CI/CD security tools.
• Experience administering or securing systems in Linux environments (Red Hat).

Original Posting:

October 14, 2026

Pay Range:

Pay Range $131,300.00 - $237,350.00

About Leidos

Leidos is an industry and technology leader serving government and commercial customers with smarter, more efficient digital and mission innovations. Headquartered in Reston, Virginia, with 47,000 global employees, Leidos reported annual revenues of approximately $16.7 billion for the fiscal year ended January 3, 2025. For more information, visit www.Leidos.com.

Pay and Benefits

Pay and benefits are fundamental to any career decision. That's why we craft compensation packages that reflect the importance of the work we do for our customers. Employment benefits include competitive compensation, Health and Wellness programs, Income Protection, Paid Leave and Retirement. More details are available at www.leidos.com/careers/pay-benefits.

Securing Your Data

Beware of fake employment opportunities using Leidos' name. Leidos will never ask you to provide payment-related information during any part of the employment application process (i.e., ask you for money), nor will Leidos ever advance money as part of the hiring process (i.e., send you a check or money order before doing any work). Further, Leidos will only communicate with you through emails that are generated by the Leidos.com automated system - never from free commercial services (e.g., Gmail, Yahoo, Hotmail) or via WhatsApp, Telegram, etc. If you received an email purporting to be from Leidos that asks for payment-related information or any other personal information (e.g., about you or your previous employer), and you are concerned about its legitimacy, please make us aware immediately by emailing us at [e-mail].

If you believe you are the victim of a scam, contact your local law enforcement and report the incident to the U.S. Federal Trade Commission.

Commitment to Non-Discrimination

All qualified applicants will receive consideration for employment without regard to sex, race, ethnicity, age, national origin, citizenship, religion, physical or mental disability, medical condition, genetic information, pregnancy, family structure, marital status, ancestry, domestic partner status, sexual orientation, gender identity or expression, veteran or military status, or any other basis prohibited by law. Leidos will also consider for employment qualified applicants with criminal histories consistent with relevant laws.

Information Systems Security Engineer (ISSE) SME