ABOUT RADIANT

Radiant is an El Segundo, CA-based startup building the world's first mass-produced, portable nuclear microreactors. The company's first reactor, Kaleidos, is a 1-megawatt, fail-safe microreactor that can be transported anywhere power is needed and run for up to 5 years without refueling. Portable nuclear power with rapid-deploy capability can replace similar-sized diesel generators and provide critical asset support for hospitals, data centers, remote sites, and military bases. Radiant's unique, practical approach to nuclear development leverages modern software engineering to rapidly deliver safe, factory-built microreactors that use existing, well-qualified materials. Founded in 2020, Radiant is on track to test its first reactor at the Idaho National Laboratory this summer, with initial customer deliveries beginning in 2028.

SENIOR NETWORK SECURITY ENGINEER

Radiant is looking for a hands-on Senior Network Security Engineer to own our network infrastructure as we scale. You will be the primary architect and administrator for our network security fabric, bridging our on-premise locations with our growing cloud footprint. This is not a "maintain the lights" role — you will lead critical infrastructure initiatives immediately, including migrating core services to a colocation facility (Equinix) and redesigning our site-to-site connectivity using Fortinet SD-WAN.

Responsibilities and Duties

• Lead the design and implementation of moving on-premise servers and network gear to a secure Equinix datacenter cage; ensure high-availability connectivity between the datacenter, HQ, and warehouse sites.

• Serve as the Subject Matter Expert (SME) for our Fortinet stack — manage and optimize FortiGate firewalls (HA pairs), FortiSwitch, and FortiAP.

• Design and manage secure connectivity (VPN/Direct Connect) between our physical infrastructure and cloud environments (AWS/Azure)

• Manage complex routing protocols (BGP, OSPF) to ensure seamless failover and optimal traffic paths across our SD-WAN fabric.

• Implement Zero Trust principles, manage VLAN segmentation, and monitor threats using FortiAnalyzer or similar tools.

Required Qualifications and Skills:

• 5+ years of network engineering experience with a heavy focus on security and hybrid environments

• Deep, hands-on experience with FortiOS — comfortable configuring HA clusters, VDOMs, and SD-WAN rules from scratch (NSE 7 certification is a strong plus)

• Solid understanding of cloud networking constructs, including VPCs, VNETs, Transit Gateways, and Security Groups

• Willingness to be hands-on with hardware when necessary — racking, cabling, and physically configuring devices in the datacenter

• Ability to troubleshoot complex connectivity issues spanning the physical layer, ISP routing, and cloud firewalls

Desired Qualifications and Skills:

• Experience connecting distributed sites (e.g., warehouses, remote offices) via SD-WAN

• Background in regulated or high-security industries

• Experience with network automation tools such as Ansible, Terraform, or Python

Work Environment

• Must work 100% onsite at El Segundo HQ.

• Must be willing to work extended hours and weekends as necessary to accomplish our mission.

Benefits and Perks

• Stock: Substantial incentive stock plan for all full-time employees.

• Medical: 100% up to base silver level plan for employee + 50% dependents, offers up to Platinum plans.

• One Medical: Sponsored memberships for employees and their dependents.

• Vision: 100% top tier plan coverage + 50% for dependents.

• Dental: 100% top tier plan coverage, orthodontia extra, 50% for dependents.

• Voluntary life, a