Cybersecurity Lead - Information System Security Manager (ISSM)

About the role

Sphinx is seeking a Cybersecurity Lead/Information System Security Manager (ISSM) to support the delivery of secure software and systems for next-generation space and defense programs. This role is ideal for a cybersecurity professional with deep experience in classified environments, RMF activities, and authorization efforts.

Responsibilities

• Leading cybersecurity efforts across assigned programs, ensuring systems meet government security requirements and accreditation objectives.
• Managing RMF activities throughout the system lifecycle, including authorization packages, security documentation, assessments, and continuous monitoring activities.
• Leading cybersecurity compliance efforts and coordinating with engineering, program, and government stakeholders to support successful authorization, accreditation, and ongoing security operations.
• Prioritizing cybersecurity within software architecture and integration, collaborating with software architects and engineering teams.
• Preparing, reviewing, and maintaining cybersecurity artifacts, plans, reports, and executive briefings.
• Supporting security assessments, audits, inspections, and government reviews.
• Identifying security risks, vulnerabilities, and compliance gaps while driving effective mitigation strategies.
• Coordinating cybersecurity incident response activities, including investigation, containment, remediation, reporting, and communication with internal stakeholders, customers, and government representatives as required.
• Collaborating with government Authorizing Officials (AOs), Security Control Assessors (SCAs), and customer security representatives to obtain and maintain system authorizations.
• Contributing to the development and improvement of cybersecurity policies, processes, and best practices across the organization.
• Staying current on evolving cybersecurity requirements, threats, and industry best practices impacting classified environments.

Requirements

• 7+ years of experience in cybersecurity, information assurance, information system security, RMF, or related security disciplines.
• 5+ years of experience supporting classified programs and secure government environments.
• 5+ years of experience with cybersecurity, compliance, and vulnerability management tools supporting accreditation and continuous monitoring activities.
• 5+ years of experience assessing, analyzing, and documenting security test results, compliance evidence, and technical findings to support authorization and accreditation efforts.
• Experience serving as an ISSM, ISSO, ISSE, or similar cybersecurity leadership role supporting classified government programs.
• Strong working knowledge of the Risk Management Framework (RMF) and associated guidance, including NIST 800-series publications, JSIG, ICD 503, CNSSI 1253, or equivalent frameworks.
• Experience developing and managing authorization packages and supporting Authority to Operate (ATO) efforts.
• Experience reviewing subcontractor security postures, validating external compliance and authorization artifacts, and establishing Interconnection Security Agreements (ISAs) to support secure data exchange across corporate, customer, and network boundaries.
• Comfortable leading security compliance activities, audits, assessments, and continuous monitoring programs.
• Experience working closely with software development and systems engineering teams in secure environments, including maintaining subcontractor coordination across multiple security and network environments.
• Hold a current IAM Level III certification or equivalent certification such as CISSP, CISM, or GSLC.
• Experience using cybersecurity tools and technologies such as ACAS, Nessus, SCAP, STIGs, audit reduction tools, or similar compliance and vulnerability management platforms.
• Strong written and verbal communication skills with the ability to engage technical and non-technical stakeholders.
• Active TS/SCI clearance and eligibility to obtain and maintain TS/SCI access.

Qualifications

• Must be a US Citizen.
• Must be able to obtain and hold a U.S. TS/SCI security clearance.

Benefits

• Competitive salary between $160,000 and $218,000 base salary.
• Meaningful equity ownership.
• Profit sharing.
• Employer 401(k) contribution.
• 100% employer-covered medical, dental, and vision insurance for you and your dependents.

Equal Opportunity Employer

Sphinx Defense is committed to providing equal employment opportunities to all employees and applicants for employment without regard to race, color, religion, sex, sexual orientation, and gender identity.