Xcimer Energy is a fusion energy company focused on commercializing laser-driven inertial confinement fusion, which it describes as the only scientifically validated form of fusion energy. The company is developing high-energy excimer laser systems designed to ignite fusion reactions using fuel derived from seawater and lithium, with the goal of delivering safe, clean, and affordable electricity that is cost-competitive with fossil fuels and renewables. Its mission centers on decarbonizing energy-intensive sectors such as artificial intelligence infrastructure, desalination, and industrial processes that require firm, always-on, carbon-free power.
Xcimer's technical approach relies on electron-beam-pumped excimer lasers combined with a pulse compression technique called Stimulated Brillouin Scattering (SBS), which compresses microsecond laser pulses to nanosecond durations without damaging optics. In 2024 the company broke ground on Phoenix, its first prototype high-energy laser system, located in Denver, Colorado, and announced the start of its operations in June 2026. Phoenix is the first electron-beam-pumped excimer laser built in the private sector in more than two decades and validates key elements of the company's low-cost laser fusion architecture.
Xcimer's longer-term target is Athena, which it describes as the world's first laser fusion power plant, expected to deliver 400 megawatts of continuous clean energy by 2035. The company has received a U.S. Department of Energy approval of its fusion power plant preconceptual design and technology roadmap milestone, and collaborates with industrial partners such as TRUMPF Laser SE. With a team of nearly 200 engineers, physicists, and business professionals, Xcimer positions itself as the most technically mature private laser fusion company.
Xcimer Energy leverages decades of research on Inertial Fusion Energy (IFE) combined with groundbreaking new laser architecture. Our mission is to deploy fusion power plants to meet global decarbonization goals as fast as possible. Xcimer has assembled a team of leaders in tough tech, fusion science, and manufacturing with a track record of rapid execution. Supported by leading investors, Xcimer is uniquely positioned to deliver limitless, clean, fusion power to combat climate change. Join us in powering a better world with inertial fusion!
This is a full-time, onsite role based at our headquarters in Denver, CO.
As a Senior Platform Engineer you will design and ship the systems, services, and paved-path tooling that let researchers and engineers move fast. The platform spans data analysis pipelines, the data warehouse, dashboards, research code environments, and the friendly interfaces that expose HPC simulation to non-specialists: a broad surface where great engineering directly accelerates discovery.
This is a hands-on, high-impact role. You will architect and write systems, treat internal tooling as a product with real users, mentor junior engineers, and make deliberate tradeoffs between speed and robustness in an R&D environment where both matter. You'll work closely with physicists, controls engineers, and software architects to turn hard research problems into reliable, reusable infrastructure.
In this role, you will build the platform behind Xcimer's path to commercially viable inertial fusion energy. You'll let PhDs and engineers spend their time on physics and engineering instead of infrastructure, with direct access to simulation, data, and analysis through tools that work reliably. Every researcher's productive day depends on the platform you build. This is a strategic leadership position tied directly to the company's mission. We are looking for our engineers to apply their technical expertise, problem solving skills, and dedication to quality to positively impact the future of energy!
Equal Employment Opportunity
Xcimer Energy is proud to be an Equal Opportunity/Affirmative Action Employer and is committed to attracting, retaining, and developing a highly qualified, diverse, and dedicated work force. Xcimer Energy hires and promotes people on the basis of their qualifications, performance, and abilities. We support the establishment and maintenance of a workplace that fosters trust, equality, and teamwork, in which all employees recognize and appreciate the diversity of individual team members. We provide all qualified applicants for employment and employees with equal opportunities for hire, promotion, and other terms and conditions of employment, regardless of their race, color, religion, gender, sexual orientation, gender identity, national origin/ethnicity, age, physical or mental disability, genetic factors, military/veteran status, or any other status or characteristic protected by federal, state, and/or local law. Xcimer Energy will consider for employment qualified applicants with criminal histories in a manner consistent with applicable federal, state, and local laws. For more information on “EEO Is the Law,” please see
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Benefits
Xcimer offers a comprehensive benefits package designed to support employee health, well-being, and long-term success. Benefits include medical, dental, and vision coverage; basic and supplemental life insurance; short- and long-term disability; paid parental leave for employees at the time of birth or adoption; and a 401(k) with a company match of up to 6%. Eligible employees also receive equity, allowing them to share in the company’s long-term success.
Xcimer operates under a flexible Paid Time Off (ATO) approach. Rather than a fixed number of vacation days, employees are trusted to take the time they need to rest and recharge while meeting the expectations of their role and team. In addition, employees receive paid sick time, 13 company-paid holidays, and an annual paid company shutdown. Benefits are available to regular employees, including part-time and fixed-term roles, as well as interns, with eligibility varying by benefit.
Responsibilities
Internal Developer Platform
Build and own the internal developer platform as a product, so researchers and engineers can provision what they need and start work quickly.
Design and build the services behind data analysis pipelines, the data warehouse, dashboards, research code environments, and the web apps that expose HPC simulation to non-specialists.
Extend Open OnDemand and related portals, and build what's missing where off-the-shelf tools fall short.
Own AI developer tooling, its budget, and provisioning workflows.
Set and maintain standards that give engineers autonomy while keeping the platform coherent and governable.
Systems & Software Engineering
Architect and write platform services, control planes, APIs, and data-pipeline frameworks.
Build reusable components and set software standards that match the needs of active R&D projects.
Translate requirements from Physics, Engineering, and Controls teams into systems that scale and stay maintainable.
Treat reliability, observability, and cost as design requirements.
HPC & Infrastructure
Provide the platform layer over HPC clusters, job scheduling, and distributed filesystems so researchers can run simulation and analysis themselves.
Build and maintain secure cloud infrastructure (AWS/GCP/Azure), managed as infrastructure-as-code.
Build observability, alerting, and incident-response systems across on-prem and cloud resources.
Manage cloud costs proactively through architecture choices, reserved capacity, and observability.
Lead migrations, upgrades, and modernization with minimal disruption to active experiments.
Documentation & Mentorship
Write clear documentation, runbooks, and operational procedures so others can operate and extend the platform.
Mentor junior platform engineers and the cross-functional engineers who build on the platform.
Set technical direction for infrastructure as code, observability, and system resilience.
Qualifications
Education: Bachelor's degree in Computer Science, Engineering, Physics, Applied Mathematics, or related field; advanced degree preferred.
Experience: 7+ years of experience in platform, infrastructure, or software engineering, including building internal tools or platforms used by other engineers.
Strong software engineering fundamentals. Proficiency in Python, Rust, and/or C++.
Experience building internal platforms or tooling that measurably improved team productivity.
Hands-on experience with Linux and infrastructure automation (Ansible, Terraform, or equivalent).
Experience with cloud infrastructure (AWS/GCP/Azure). Familiarity with HPC clusters and job scheduling is a plus.
A track record of designing systems for reliability, observability, and scale.
Experience with containerization and orchestration (Kubernetes, Docker, or similar).
Experience mentoring engineers and leading cross-functional projects.
Clear communication, including explaining technical tradeoffs to non-technical colleagues.
Must be a U.S. citizen or national, U.S. permanent resident (current Green Card holder), or lawfully admitted into the U.S. as a refugee of granted asylum
Desired
Experience building data platforms, data warehouses, or analytics and dashboard infrastructure.
Prior experience in scientific computing or research environments.
Familiarity with Open OnDemand or similar research computing portals.
Experience with secure enclave architectures, identity management (OIDC, LDAP), or export-controlled data.
Domain background in manufacturing, experimental physics, or fusion energy. We don't require it — strong generalists ramp quickly here — but a head start is welcome.
Experience managing and optimizing cloud infrastructure.
