Senior System Administrator

Radiant • El Segundo, CA

91d

About The Position

Radiant is seeking a Senior System Administrator to join our growing team. In this role, you’ll help build and maintain the core infrastructure that supports the development, testing, and operation of our microreactor systems. You'll be a key technical contributor, ensuring our systems are secure, scalable, and reliable. You will have an opportunity to work in an interdisciplinary environment with a high degree of ownership and drive milestones forward to unlock commercialization of the first mass-produced nuclear reactor.

Requirements

• Bachelor’s degree in computer science or engineering
• 5+ years of professional experience as a system administrator or infrastructure engineer
• Strong Windows and Linux system administration skills in production environments
• In-depth understanding of networking concepts (TCP/IP, routing, DNS, firewalls) and storage systems
• Proficiency in scripting or programming languages (e.g., Bash, Python, Power Automate) for automation
• Experience with infrastructure as code tools (e.g., Terraform, Ansible, or similar)
• Experience with PLCs (like Beckhoff or Rockwell Automation)
• Ability to work from Radiant’s office in El Segundo, CA (greater Los Angeles) full-time

Nice To Haves

• Highly self-motivated with strong communication skills
• Experience testing software and hardware systems
• Familiarity with real-time systems, embedded environments, or hardware/software integration
• Prior work in regulated or high-assurance environments (e.g., nuclear, aerospace, defense, healthcare)

Responsibilities

• Design, deploy, and maintain Radiant’s server, storage, and network infrastructure (including hybrid cloud and on-prem environments)
• Ensure high availability, performance, and disaster recovery for critical systems and services
• Implement and maintain system security, including patching, access control, hardening, and vulnerability management
• Troubleshoot and resolve infrastructure incidents, performing root cause analysis and corrective action
• Collaborate with mechanical and production teams to install and configure PLCs, DAQs and set up operator stations
• Mentor junior team members and contribute to the development of infrastructure best practices across the organization

Benefits

• Substantial incentive stock plan for all full-time employees
• 100% up to base silver level plan for employee + 50% dependents, offers up to Platinum plans
• Sponsored memberships for employees and their dependents with One Medical
• 100% top tier plan coverage + 50% for dependents for vision
• 100% top tier plan coverage, orthodontia extra, 50% for dependents for dental
• Voluntary life, accident, hospital, critical illness, commuter and FSA/HSA are offered as employee contributed benefits
• 8-weeks of paid parental leave for all parents, additional paid pregnancy leave for CA employees
• Daily catered lunch, free snacks and drinks
• Flexible PTO policy, remote workday allocation
• Company and team-bonding events, happy hours and in-person camaraderie
• Beautiful El Segundo headquarters close to the Pacific Ocean

What This Job Offers

• Job Type: Full-time
• Career Level: Mid Level
• Education Level: Bachelor's degree
• Number of Employees: 101-250 employees