Senior Cybersecurity Analyst

Castelion Corporation•Torrance, CA

1d•Onsite

About The Position

Castelion is seeking an experienced Senior Cybersecurity Analyst to protect sensitive systems, data, and infrastructure critical to national security. The role focuses on threat detection, security operations center (SOC) work, incident response, threat analysis, and compliance with requirements relevant to the defense industrial base. The analyst will work across IT, engineering, manufacturing, and program teams, and contribute to team development by mentoring junior analysts. The role is based in Torrance, California, and requires full-time onsite presence. Extended hours, including evenings and weekends, may be required to meet aggressive timelines. The position requires access to export-controlled information; hiring is contingent on the candidate’s ability to access applicable information without additional export licensing. U.S. Person status is required for ITAR compliance, and the candidate must be able to obtain and maintain a U.S. security clearance if required for the role.

Requirements

At least 3 years of experience in cybersecurity, information security, or related technical security roles.
Hands-on experience with security operations, incident response, and threat analysis.
Expert knowledge of SIEM tools such as Splunk, QRadar, or Sentinel; EDR tools such as CrowdStrike or Carbon Black; and IDS/IPS.
Deep knowledge of the MITRE ATT&CK framework and adversary tactics, techniques, and procedures.
Familiarity with threat intelligence platforms and OSINT techniques.
Experience protecting Controlled Unclassified Information (CUI).
Experience in aerospace, defense, national security, government contracting, or highly regulated technical environments.
Strong understanding of network protocols, Windows and Linux operating systems, and cloud environments.
Experience as a member of incident response protocols, vulnerability management, and security operations functions.
Proficiency in scripting and automation.
U.S. Person status required to comply with ITAR regulations.
Ability to obtain and maintain a U.S. security clearance.
Ability to work extended hours, including evenings and weekends, when required.
Ability to access applicable export-controlled information without additional export licensing.

Nice To Haves

Experience supporting defense manufacturing or operational technology (OT/ICS) environments.
Experience securing embedded systems, avionics, autonomous systems, or weapon systems.
Experience at high-growth startups or scaling organizations.
Hands-on experience implementing SIEM and SOAR operations.
Experience with CMMC 2.0, NIST SP 800-171, DFARS 252.204-7012/7020/7021, ITAR, and related defense compliance requirements.
Industry certifications such as Security+, CEH, CISA, GIAC, or equivalent.
Degree in Cybersecurity, Computer Science, Engineering, or a related field.

Responsibilities

Lead 24/7 security monitoring using SIEM platforms and advanced threat detection tools.
Analyze security events, identify potential threats, and coordinate incident response activities.
Identify vulnerabilities and recommend remediation strategies for complex environments.
Analyze malware, advanced persistent threat (APT) tactics, and threat actor behavior.
Conduct threat hunting to proactively identify sophisticated adversaries.
Perform forensic analysis of incidents involving classified and sensitive systems.
Contribute to compliance with NIST 800-171, CMMC, DFARS, ITAR, and other DoD requirements.
Contribute to or maintain security documentation, including internal documentation, policies, procedures, incident reports, and audit artifacts.
Configure and maintain security tools, including IDS/IPS, EDR, DLP, and vulnerability scanners.
Support secure architecture reviews across the organization.
Mentor junior analysts and contribute to team skill development.
Coordinate security initiatives with IT, engineering, manufacturing, and program teams.
Participate in threat intelligence sharing with government and industry partners.