Senior Security Engineer

About Pacific Fusion Pacific Fusion was founded in 2023 with the mission to power the world with abundant, affordable, clean energy. We are rapidly designing and building a pulser-driven inertial fusion system to achieve net facility gain (more fusion energy output than stored energy input). In parallel, we are developing the key components required to build affordable fusion systems. Our plans are ambitious. We have raised over $900M so far from incredible investors, resourcing us to deliver on these plans. We are bringing together the best scientists, engineers, and operators from the fusion community, hard tech industry, and other sectors. We are united by a shared sense of urgency to provide clean power for the world, particularly managing climate change while meeting growing global energy demand. You can read more about us in this letter from our founders . Why This Role Matters The Senior Security Engineer will implement, monitor, and maintain security controls across Pacific Fusion's information technology systems, spanning corporate IT, cloud infrastructure, and SaaS applications. This role ensures critical business applications are securely configured, security policies are enforced, and both company-owned and BYOD devices meet security and compliance requirements. Working closely with IT, operations, and business application owners, the Senior Security Engineer will design access controls, oversee security configuration baselines, respond to security incidents, and produce the evidence and documentation underpinning our compliance program. This is a builder role in a growing hybrid environment of SaaS services, on-premise systems, and diverse endpoints across multiple sites. What You'll Do Configure and maintain security settings for critical SaaS applications, including identity, collaboration, productivity, and business operations platforms. Manage and enforce mobile device management policies for company-owned and BYOD devices, including compliance policies that gate access to controlled data. Oversee endpoint security for Windows, macOS, and mobile devices, including patching, encryption, and threat protection. Implement and maintain secure authentication and access control policies, including MFA and conditional access aligned to NIST technical controls. Conduct regular security reviews of SaaS configurations and device compliance reports. Monitor for security incidents across endpoints, mobile devices, and SaaS applications; investigate, remediate, and document per incident response procedures. Maintain documentation of security controls, policies, and incident response procedures. Collaborate with IT and organizational stakeholders to design security protocols that empower business operations and productivity. Support System Security Plan (SSP) development by documenting how controls are implemented in systems you own. What You Bring 5+ years of experience in IT security, endpoint management, or related fields. Strong knowledge of SaaS application administration and security configuration best practices. Experience with identity and access management, MFA, and conditional access policies (Microsoft Entra ID experience strongly preferred). Understanding of endpoint protection technologies, patch management, and encryption. Experience investigating and remediating security incidents, and documenting the investigation. Strong communication skills and ability to work across technical and non-technical teams. Hands-on experience with MDM solutions (e.g. Microsoft Intune, JAMF, Kandji) for device enrollment, configuration, and compliance management Bonus Points For Experience with security assessments and compliance frameworks (e.g., NIST 800-171, CMMC L2. SOC 2, ISO 27001). Experience producing audit evidence for compliance frameworks (NIST 800-171, SOC 2, ISO 27001) or cyber insurance assessments. Experience with SIEM tools or centralized logging platforms. Scripting or automation experience (PowerShell, Python).…