Senior Cybersecurity Engineer (IAM)

Amentum is a global leader in advanced engineering and innovative technology solutions, trusted by the United States and its allies to address their most significant and complex challenges in science, security and sustainability. Our people apply undaunted curiosity, relentless ambition and boundless imagination to challenge convention and drive progress. Our commitments are underpinned by the belief that safety, collaboration and well-being are integral to success. Headquartered in Chantilly, Virginia, we have approximately 50,000 employees in more than 70 countries across all 7 continents.

Amentum is seeking a Senior Cybersecurity Engineer with deep Identity and Access Management (IAM) expertise to protect enterprise assets across a multi-tenant, hybrid (cloud/on-premises) environment. This is a fully remote, hands-on role spanning identity security, multi-cloud security, and endpoint protection. This position is US Remote telework and US Citizenship is required.

Responsibilities

• Implement and operate enterprise IAM security controls across a multi-tenant/multi-domain hybrid environment spanning Entra ID, Okta, and Active Directory — including PAM, JIT access, conditional access, and MFA policy enforcement (not day-to-day user/group provisioning or account administration)
• Execute IAM designs defined by security architecture, translating architectural standards into working security configurations, policies, and integrations
• Maintain and enforce IAM-related security policies, standards, and best practices in alignment with regulatory and compliance requirements (CMMC, NIST 800-171/800-172, and other applicable frameworks)
• Configure and tune identity security controls — access policies, privileged access workflows, authentication requirements — protecting users, systems, applications, and data across Entra ID, Okta, and AD environments
• Serve as 2nd-level SOC escalation point for critical identity-rela