Senior Software Engineer, Frontend

About Radiant Radiant is an El Segundo, CA-based startup building the world’s first mass-produced, portable nuclear microreactors. Rising energy demand is straining the U.S. grid and driving up utility costs, emissions, and interconnection backlogs. Radiant decentralizes energy, producing power close to where it’s used. Its first reactor, Kaleidos, is a factory-built, 1-megawatt, fail-safe microreactor that can be transported by land, sea, or air and runs up to 5 years without refueling.

Deployed locally without a decade-long build or permitting fight, Kaleidos provides independent power for critical infrastructure like military bases, data centers, hospitals, and remote sites. Founded in 2020, Radiant is under contract to deliver power to the U.S. Army, Air Force, Navy, and has pre-order agreements with Equinix, with deployments beginning in 2028.About the Role Radiant is seeking a Senior Software Engineer to own the frontend for our in-house telemetry and fleet management platform.

You’ll join the Mission Software team, build on top of a highly technical telemetry streaming platform, and work on fleet monitoring systems for Radiant’s portable nuclear reactor, Kaleidos. You’ll also build additional features for engineers and operators, adding new data analysis and configuration capabilities to a critical platform. The ideal candidate is outgoing and organized, ready to collaborate with other engineers.

The code you write will help design, run, and mass-produce the first high-temperature gas-cooled portable microreactor ever to be commercialized.

Responsibilities & Duties Own critical parts of the frontend for our internal telemetry and fleet management platform, working in a modern React + Type Script + Vite codebase.

Develop highly reliable, performant systems for data review and analysis.

Develop frontend pages for complex device configuration and telemetry systems.

Collaborate with other members of the Mission Software team and reach consensus among stakeholders across the company.

Required Qualifications & Skills Bachelor's degree in Computer Science, Engineering, Physics, or a related technical field.
5+ years of professional experience in web development, frontend development, and / or desktop GUI development.

Proficient in using React + Type Script for SPAs, testing with Vitest + Playwright Experience building highly performant, complex, mission-critical systems using technologies like Web Sockets, WebRTC, or SSE.Has worked on a complicated UI system before, driving forward critical features

Strong code review & debugging skills.

Desired

Qualifications & Skills Experience using the following technologies:
Tan Stack Query + React Router, Pixi.js + WebGPU, Yjs or similar CRDTHMI or dashboarding design experience

Hands-on hardware tech experience, working closely with hardware engineers to develop deeply coupled applications.

Our Tech Stack:

Typescript React Vite Pixi .js & Yjs Rust + Axum Web / Python + FastAPI

Additional Requirements:

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

Must work 100% onsite at El Segundo HQ.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, 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…