Information System Security Jobs in California (NOW HIRING)

TThe Information System Security Officer (ISSO), in collaboration with the Information System Security Manager (ISSM), supports the security and compliance of the organization's classified and high-side information systems while enabling mission-critical operations. This role is ideal for a junior to mid-level cybersecurity professional with foundational knowledge of information assurance, system administration, security compliance, and DoD or DCSA security requirements. The ISSO assists with securing on-premises networks, standalone systems, business applications, and peripherals through hands-on execution of security procedures, continuous monitoring, documentation, and customer support. Responsibilities include supporting Risk Management Framework (RMF) activities and Authorization to Operate (ATO) package development and maintenance through eMASS and associated processes, while partnering with industrial security and technical teams to implement technical, administrative, and operational controls.

Success in this role requires a willingness to learn, attention to detail, clear communication, initiative, and the ability to think creatively when balancing security requirements with operational needs. The successful candidate will be highly personable, approachable, and able to independently build relationships with customers, end users, and internal cross-functional teams. Candidates should be self-starters with basic system administration experience or technical aptitude and an interest in growing their cybersecurity and compliance expertise. This is a full-time, on-site position requiring face-to-face collaboration with cross-functional teams and colleagues. Early career candidates with security clearances are highly encouraged to apply! 

• Serve as the ISSO under the direction of the ISSM, overseeing the security compliance and secure operations for the full lifecycle of classified systems in alignment with Defense Counterintelligence and Security Agency (DCSA) and other federal government standards
• Act as an advisor to the Site Facility Security Officer (FSO) and ISSM on all classified information system security matters and maintain liaison with the local DCSA Information Systems Security Professional (ISSP)
• Ensure ongoing compliance with the National Industrial Security Program (NISP), DoD, and DCSA requirements by executing local policies, processes, and procedures in alignment with the DCSA Assessment and Authorization Guide (DAAG)
• Execute steps within RMF, developing and maintaining required security documentation and artifacts, including policies, procedures, training materials, security control implementation, system diagrams, asset inventories, and Plans of Action and Milestones (POA&Ms)
• Maintain and renew ATOs for classified systems, ensuring full alignment with DoD, DCSA, and corporate requirements
• Collaborate with DCSA ISSP and internal stakeholders to resolve assessment findings and strengthen the overall security posture and compliance adherence
• Conduct periodic self-inspections and security assessments of classified systems as part of the facility's self- inspection program, ensuring corrective actions are implemented promptly
• Assist in preparing for and supporting internal and external audits by government agencies through updating documentation, validating configurations, preparing physical artifacts, and ensuring NIST security controls remain compliant
• Identify, document, and mitigate local threats and vulnerabilities to classified information systems, ensuring timely remediation of all identified risks
• Support the ISSM in delivering site-wide information systems security education and awareness programs to all users of classified systems supporting secured contracts
• Assist in investigations of security violations related to classified systems, ensuring corrective actions are documented and implemented
• Collaborate cross-functionally with program management, facilities, human resources, IT, and other stakeholders to execute security deliverables and support personnel requirements
• Perform vulnerability scanning using approved tools (e.g., Nessus), analyze results, assess risks, and develop mitigation strategies in accordance with established timelines 

Security Administration and Operations:

• Perform regular backups, troubleshoot issues, and maintain availability of virtual and physical storage systems.
• Install patches, firmware, and software upgrades for servers and related hardware to maintain security, performance, and compliance.
• Serve as a designated Data Transfer Agent (DTA) for authorized transfers across classification environments.
• Provide on-site technical support to cross-functional teams and troubleshoot moderately complex system and application issues.
• Monitor and enforce access controls for cleared systems supporting classified programs, consistent with least-privilege principles.
• Administer end-user accounts through onboarding, role changes, and offboarding in accordance with authorization protocols.
• Conduct scheduled audits of system configurations, processes, and procedures to verify compliance, security posture, and readiness.
• Perform additional duties as directed by the ISSM, Senior System Administrator, ISSO, or FSO in support of the organization's mission and security culture.
• Other duties as assigned. 

Information System Security Compliance Competency

• Familiarity with assembling and managing RMF security authorization packages and supporting artifacts, preferably in a DoD environment, using eMASS; experience supporting ATOs and continuous monitoring is preferred.
• Working knowledge of implementing technical security controls and hardening standards, including STIGs and SCAP; familiarity with executing and reviewing vulnerability scans, such as Nessus or ACAS, and
• supporting risk-based remediation.
• Strong technical writing skills to produce clear, concise security documentation, policies, procedures, and formal memoranda.
• Ability to work collaboratively with industrial security professionals and FSOs while applying NISP and DCSA requirements.

Security Administration and Operations

• Basic to intermediate experience administering and maintaining servers, primarily Windows, including patching, configuration management, auditing, and STIG-based hardening; exposure to Splunk or similar tools and virtualized environments is preferred.
• Hands-on experience or foundational knowledge of securing and managing Windows endpoints and Cisco network devices, including configuration, access control, and basic network troubleshooting.
• Familiarity with cross-domain and data transfer activities across classification levels in accordance with established policy and security controls.

Problem Solving and Initiative

• Strong analytical and troubleshooting skills with a proactive, self-starting mindset; able to independently identify, research, and help resolve technical and compliance issues.
• Ability to prioritize competing tasks, follow through to completion, and seek guidance when needed in support of mission objectives.
• Eagerness to learn, adapt, and think creatively when balancing security requirements with operational needs.

Customer Service and Communication Competencies

• Strong interpersonal, oral, and written communication skills, with the ability to provide professional face-to-face support and clearly communicate technical and security information to stakeholders at all levels.
• A personable and approachable communicator who can independently build productive relationships with customers, end users, and internal cross-functional teams.
• Ability to coordinate with functional teams to translate security requirements into practical operational solutions and foster collaborative working relationships. 

• Active DoD Secret security clearance required, with the ability to obtain and maintain a Top Secret clearance throughout employment.
• Associate's degree in computer science, cybersecurity, or a related field; equivalent relevant experience may be considered. CompTIA Security+ certification is required. CISSP, CISA, or GIAC certifications are a plus.
• Three or more years of experience in information security, information systems security, the defense industry, or a related technical field; equivalent combinations of education and experience may be considered.
• Foundational knowledge of U.S. Government information system security standards, including NIST and ISO 27001, and familiarity with federal cybersecurity compliance, security authorization, continuous monitoring, and basic system security administration.
• Knowledge of information system security components and best practices, including firewalls, intrusion detection systems, endpoint protection, data encryption, and other industry-standard security techniques.
• Highly self-motivated, organized, detail-oriented, and willing to learn and grow in an ISSO role.
• Strong face-to-face interpersonal and communication skills, with the ability to clearly explain security requirements, build relationships with customers and internal teams, support audits, and guide personnel on security best practices.
• Ability to work independently, take direction, accept coaching and mentorship, and adapt to the needs, working style, and priorities of the team and organization.
• Ability to interact professionally with all levels of management, IT professionals, customers, and end users.
• Strong analytical, troubleshooting, and problem-solving skills, with the ability to think creatively and identify practical solutions.
• Adaptable and responsive to change, with a commitment to continuous improvement and customer-focused support.