Senior Cybersecurity Engineer — TS/SCI Clearance

Cornerstone Defense; Reston (VA); On-site; USD 140,000 - 180,000; Full time

Job summary

Cornerstone Defense is seeking a Sr. Cybersecurity Engineer in Reston, VA to safeguard sensitive information and design, implement, and maintain our cybersecurity infrastructure.

This role requires an Active TS/SCI clearance with CI poly and a strong background in current threats, vulnerabilities, and proactive security controls. The ideal candidate will contribute to cross-functional teams, ensure security across development lifecycles, and stay current with evolving security trends while

Qualifications

• 7+ years of experience as a cybersecurity engineer with expertise in implementing security controls and continuous monitoring for compliance.
• Strong experience collecting and querying logs in Splunk to identify anomalies and risks.
• Experience implementing controls per NIST SP 800-53, RMF, ICD 503, FISMA, FedRAMP.
• Experience with cloud, container, and DevSecOps in IL5 to IL6+ environments.
• Proficient in incident response, security incident handling, and forensic analysis.

Responsibilities

• Design, implement, and manage security solutions (firewalls, IDS/IPS, endpoint protection, encryption).
• Conduct regular security assessments to identify vulnerabilities.
• Develop and implement incident response plans for security breaches.
• Collaborate with IT, software development, and compliance to enforce security policies.
• Monitor traffic, logs, and alerts to detect and respond to incidents.
• Maintain documentation and produce detailed security reports.

Skills

Security governance

log analysis

incident response

NIST RMF / FedRAMP

DevSecOps

Cloud security IL5-IL6+

forensic analysis

communication

security controls design

risk assessment

Tools

Splunk

Fortify

Acunetix

Prisma Cloud

Job description

Cornerstone Defense is seeking a Sr. Cybersecurity Engineer in Reston, VA to safeguard sensitive information and design, implement, and maintain our cybersecurity infrastructure.

This role requires an Active TS/SCI clearance with CI poly and a strong background in current threats, vulnerabilities, and proactive security controls. The ideal candidate will contribute to cross-functional teams, ensure security across development lifecycles, and stay current with evolving security trends while