Senior Software Engineer, Full Stack

You will design, develop, and operate secure, reliable, scalable, and delightfully usable full-stack applications to optimize processes between mechanical and electrical engineering, supply chain, inventory, manufacturing, and finance, integrating with our internal data platform and external systems. This is a high-impact, high-visibility role: together with a cross-functional team owning business critical applications, you will multiply the impact of many other teams across the company. You will: Design and develop frontends, APIs, workflows, database schemas, and caching layers Be a part-time product manager and UX designer. You need to understand how people and processes interact with the software you build Monitor and continuously improve the performance and reliability of our systems, using best-in-class observability tools Collaborate with other software engineers, data analysts and scientists, other engineering disciplines, non-engineers, leadership, and vendors to understand feature and data requirements and deliver solutions Stay current with emerging technologies while recommending battle-tested right-fit solutions that align with strategic goals Participate in on-call rotations to maintain our SLA with the rest of the company, and prevent issues from stalling 24/7 production schedules

Bachelor's degree in computer science or a related field 8+ years of software engineering experience building full-stack applications Hands-on experience with modern web stacks (e.g., React, Next.js) Expertise in HTML, CSS, TypeScript and a backend language like Go or Python Cloud-native experience in Azure, AWS, and/or Google Cloud, using container orchestration technologies like Docker, Kubernetes, and infrastructure-as-code tools like Terraform Familiar with DevOps best practices, using version control (Git), CI/CD (e.g., Buildkite, GitHub Actions), and monitoring and alerting (e.g., Prometheus, Grafana, Datadog) Familiar with UX design tools like Figma

Our total compensation package includes benefits, including but not limited to:

• Medical, Dental, and Vision plans for employees and their families
• 31 Days of PTO (21 vacation days and 10 sick days)
• 10 Paid holidays, plus company-wide winter break
• Up to 5% employer 401(k) match
• Short term disability, long term disability, and life insurance
• Paid parental leave and support (up to 16 weeks)
• Annual wellness stipend

About Helion We are a fusion power company based in Everett, WA, with the mission to build the world's first fusion power plant, enabling a future with unlimited clean electricity. Our vision is a world with clean, reliable, and affordable energy for everyone. Since Helion's founding in 2013, we have raised over $1 billion from long-time investors such as Sam Altman, Mithril, and Capricorn Investment Group as well as new investors SoftBank and Lightspeed to propel us forward. Our last prototype, Trenta, completed 10,000 high-power pulses and reached plasma temperatures of 100 million degrees Celsius (9 keV). We are now operating Polaris, our next prototype on the path to the world's first fusion power plant. This is a pivotal time to join Helion. You will tackle real-world challenges with a team that prizes urgency, rigor, ownership, and a commitment to delivering hard truths - values essential to achieving what no one has before. Together, we will change the future of energy, because the world can't wait. What you will be doing, © 2026 Careerjet All rights reserved