Senior Systems Administrator

The Nuclear Company is the fastest growing AI tech-enabled startup in the nuclear and energy space, pioneering a fleet-scale approach to building the next generation of nuclear reactors. Through our design-once, build-many model, we're accelerating the deployment of safe, reliable, and affordable nuclear energy. We operate with an AI-first mindset. Every employee is expected to leverage AI, technology, and the Nuclear Operating System (NOS) as integral components of their role to improve the quality, speed, and impact of their work. We expect every team member to continuously identify opportunities to automate workflows, enhance decision-making, improve processes, and contribute to the ongoing evolution of NOS as a strategic operating capability that enables The Nuclear Company to scale with excellence. We hire people who are driven by purpose, thrive in ambiguity, and are energized by building what has never been built before. Our team combines intellectual curiosity with high agency, embraces candid feedback and continuous learning, and holds themselves and others to exceptional standards. Our values— Transparency, Responsibility, Unity, Scrappy, and Tenacity —guide how we hire, collaborate, and make decisions every day. They are not words on a wall; they are the standard by which we operate. TRUST is the foundation of our safety culture, fostering intellectual honesty, accountability, and open communication, while our values challenge every team member to execute with urgency, humility, resilience, and an unwavering commitment to our mission. About the role The Nuclear Company is seeking a Senior Systems Administrator to securely administer and scale Microsoft 365, Microsoft Entra ID, managed endpoints, AWS, and Windows/Linux server environments. This role serves as the primary administrator and Tier 3 escalation point for assigned platforms, remediates legacy configuration risks, and builds automation that makes provisioning, compliance evidence, and reporting repeatable. The Senior Systems Administrator partners with Infrastructure, Cybersecurity, HR, Legal, and Engineering to maintain reliable, auditable services and support the organization's compliance and audit-readiness objectives. The ideal candidate is a hands-on technical professional with a security-first mindset who moves effectively in a fast-paced environment and automates high-value, repeatable work. Responsibilities Microsoft 365 and Identity Administration Administer and securely scale Microsoft 365, including Exchange Online, SharePoint Online, mail flow, retention, sharing, and licensing. Administer Microsoft Entra ID, SSO, MFA, Conditional Access, role-based access control, privileged access, and user lifecycle processes. Audit user and administrator accounts, security groups, roles, and licenses; remediate orphaned identities, excessive access, and legacy configuration issues. Configure and operate assigned DLP and insider-risk technical controls in partnership with Cybersecurity and Legal and in accordance with approved policies and applicable requirements. Endpoint and Device Lifecycle Management Standardize enrollment and compliance through Intune across Windows, macOS, and iOS, and use NinjaOne or another approved RMM platform for supported endpoint monitoring and management. Maintain device naming, security baselines, configuration policies, patching, software deployment, inventory accuracy, and remediation workflows. Support the complete device lifecycle, including onboarding, refresh, reassignment, and secure offboarding. Cloud and Server Administration Administer and maintain Microsoft Azure and AWS environments, with Azure serving as a primary enterprise platform. Establish scalable standards across both platforms for identity and access management, security configuration, logging, monitoring, backup, and recovery to support current operations and future growth. Administer Windows Server and Linux environments, including Active Directory, Group Policy, DNS, DHCP, system hardening, patching, and operational monitoring. Maintain system backup and recovery procedures, perform documented restoration tests, and support execution of disaster recovery plans owned by the Manager, Infrastructure & Operations. Automation and Process Improvement Build PowerShell automation, supplemented by Bash or Python where appropriate, for provisioning, compliance validation, reporting, and routine administration. Develop repeatable, scalable processes for system deployment, configuration management, and lifecycle administration. Use approved AI-assisted tools responsibly to improve scripting, troubleshooting, documentation, and operational reliability. Maintain current procedures, system documentation, runbooks, and evidence needed for operational continuity and audits. Tier 3 Escalation and Cross-Functional Support Serve as the Tier 3 escalation point for complex Microsoft 365, identity, endpoint, AWS, and server issues within the role's assigned scope. Lead multi-system troubleshooting and coordinate handoffs to Infrastructure, Network, Cybersecurity, application owners, or vendors when issues cross ownership boundaries. Partner with HR, Legal, Engineering, and other business functions on onboarding, offboarding, access, automation, and audit-readiness initiatives. Provide technical guidance and reusable troubleshooting documentation to IT Support Specialists. Experience Bachelor's degree in Computer Science, Information Technology, or a related field, or equivalent practical experience, plus at least 5 years of progressive systems administration experience. Strong Microsoft 365 and Microsoft Entra ID administration experience, including Exchange Online, SharePoint Online, Conditional Access, security groups, RBAC, licensing, and identity lifecycle management. Hands-on endpoint and server administration experience using Intune across Windows, macOS, and iOS; Windows Server, Active Directory, and Group Policy; and familiarity with RMM concepts. Advanced PowerShell automation skills, a solid command of networking fundamentals (TCP/IP, DNS, DHCP, and VLANs), and a disciplined troubleshooting approach for complex, multi-system issues; ability to use approved AI-assisted tools responsibly in technical workflows. Preferred Experience Experience with zero-trust architecture, privileged identity management, or Microsoft Purview information-protection capabilities. Experience in a regulated or high-assurance environment such as nuclear, energy, defense, or the federal sector. Familiarity with frameworks and requirements such as NIST SP 800-53, CMMC, NRC cybersecurity guidance, or 10 CFR 73.54. Familiarity with automation or configuration-management tools beyond PowerShell, such as Bash, Python, Terraform, or Ansible Experience with NinjaOne or a comparable RMM platform; knowledge of ITIL or similar service-management practices; and experience with observability or AIOps platforms. Competitive compensation packages 401k with company match Estimated Starting Salary Range The estimated starting salary range for this role is $121,000 - $143,000 annually less applicable withholdings and deductions, paid on a bi-weekly basis. The actual salary offered may vary based on relevant factors as determined in the Company’s discretion, which may include experience, qualifications, tenure, skill set, availability of qualified candidates, geographic location, certifications held, and other criteria deemed pertinent to the particular role. EEO Statement The Nuclear Company is an equal opportunity employer committed to fostering an environment of inclusion in the workplace. We provide equal employment opportunities to all qualified applicants and employees without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, age, disability, veteran status, or any other protected characteristic. We prohibit discrimination in all aspects of employment, including hiring, promotion, demotion, transfer, compensation, and termination. Export Control Certain positions at The Nuclear Company may involve access to information and technology subject to export controls under U.S. law. Compliance with these export controls may result in The Nuclear Company limiting its consideration of certain applicants. #J-18808-Ljbffr