Principal Software Engineer (HPC DevOps)

Join Radiant, a pioneering company in the field of high-temperature gas-cooled portable microreactors. As a Principal Software Engineer, you will lead high-performance compute initiatives, manage scientific computing workflows, and serve as the primary liaison between engineering and software teams. You will work closely with the software team to design scalable, secure, and resilient compute practices, tools, and systems across the organization. This is a unique opportunity to make a significant impact in the field of clean energy and advanced technology.

• Diriger les initiatives HPC en collaboration avec l'organisation logicielle, en établissant les responsabilités, la portée du projet et le mentorat technique.
• Posséder les flux de travail, les outils et les performances pour le calcul scientifique, y compris Ansys, STAR-CCM+ et Abaqus, en couvrant la licence, la configuration de l'environnement, l'orchestration des travaux et l'infrastructure des résultats.
• Servir d'intermédiaire entre les équipes d'ingénierie et les logiciels, en répondant aux questions HPC, aux problèmes de logiciels de simulation et aux besoins d'infrastructure.
• The ideal candidate is patient, organized, and comfortable managing high volumes of cross-disciplinary requests, capable of diving deep into complex legacy stacks and synthesizing findings
• Bachelor's degree in Computer Science, Engineering, Physics or a related technical field
• Hands-on experience with HPC environments, simulation workloads, or academic/research computing (SLURM, PBS, MPI, Lustre, EFS, AWS ParallelCluster, or similar)
• 8+ years of professional experience in HPC, scientific computing, infrastructure, or platform engineering
• Deep Linux and sysadmin fluency, file systems, process management, and networking, with a hard-science approach to problem-solving
• Strong code review skills, including the ability to read stack traces and chase down dense rabbit holes in high-compliance, legacy scientific software environments
• Exceptional communication skills; organized and effective when fielding a high volume of questions and requests from engineering stakeholders
• Strong proficiency in one or more languages: Python, Golang, Rust, C#, or C/C++
• Ability to dive deep into complex, nested legacy stacks and then zoom out to synthesize findings clearly for a broader technical audience
• Master's degree or higher in Computer Science, Engineering, Physics, or a related technical field
• Hands-on physical infrastructure experience: server hardware, rack configuration, data center ops, or high-throughput networking (InfiniBand, Slingshot, AWS EFA)
• Experience working cross-functionally with engineering teams across mechanical, electrical, materials, and nuclear disciplines
• Working experience with Kubernetes and Docker for orchestration and deployment
• Experience with adjacent HPC domains, AI/ML training infrastructure, edge computing, quantum computing, visual computing (render farms), or big data analytics, where distributed hardware, GPU acceleration, and large-scale compute requirements overlap with traditional HPC environments
• Cloud infrastructure experience with Ansible, Terraform, or AWS in a cloud-native or hybrid environment
• Comfortable picking up frontend work when needed, React or general JavaScript experience is a plus; an open mind toward full-stack contributions is more important than depth here
• Must work 100% onsite at El Segundo HQ
• Must be willing to work extended hours and weekends as necessary to accomplish our mission