Senior Mechanical Engineer

About Avalanche Energy

Avalanche Energy is a Washington-based startup building compact, deployable fusion systems through rapid hardware iteration. Rather than pursuing fusion as a single grid-scale outcome, Avalanche develops transportable fusion machines designed to be built, tested, and operated on short cycles, turning real hardware into steady progress. This approach enables near-term applications that demand extreme energy density and endurance—starting with fusion neutron production for radioisotope power and other defense and space uses—while advancing the underlying fusion platform. Backed by U.S. government programs and a team experienced in delivering complex systems, Avalanche is focused on building fusion that runs in the real world, not just on paper.

About the Role

Avalanche Energy is seeking a senior mechanical leader to take full ownership of mechanical system execution at FusionWERX, our flagship fusion test facility in Richland, Washington. FusionWERX will serve as a first-of-its-kind commercial-scale testing facility for advanced fusion technologies, offering access to private companies, universities, national laboratories, and public-private consortia working to accelerate the path to commercial fusion power. This role is foundational to the next phase of Avalanche’s technical roadmap and will directly enable higher-power, higher-complexity fusion experiments.

This is not a narrow design role. You will operate as the facility mechanical owner, primary site mechanical technical lead, and on-site integrator, responsible for standing up and operating critical mechanical infrastructure, including a new tritium handling system. You will plan, execute, and coordinate across vendors, safety, facilities, and experiment teams with a high degree of autonomy and authority.

This job might be for you if:

You want to directly enable the decarbonization of the economy by building real fusion hardware, not just designing it. You are motivated by ownership and responsibility, and you are comfortable being accountable for complex mechanical systems that must work safely and reliably. You are effective in environments with ambiguity, where requirements evolve and judgment matters, and you can translate incomplete information into executable plans. You enjoy planning and execution as much as technical problem solving, thrive with high autonomy, and work well across disciplines, vendors, and safety organizations. You are persistent, pragmatic, and collaborative, and you want to play a central role in standing up a first-of-its-kind fusion testing facility.

Responsibilities (Near Term):

- Own the mechanical system definition and execution of the tritium handling system

- Translate technical and safety requirements into vendor scope and enforce them

- Manage mechanical interfaces between the tritium system, facility infrastructure, safety systems, and experiment hardware

- Lead technical reviews with subcontractors and support fabrication, installation, and acceptance

- Coordinate on-site mechanical work at FusionWERX, including routing, space claims, and sequencing

- Act as the primary mechanical point of contact for vendors, facilities work, and project integration

- Oversee project and facilities management activities to bring the facility online on schedule and within budget

- Initial onboarding includes significant time with the mechanical team in Seattle (50% + for the first 3-6 months)

Responsibilities (Long Term):

- Serve as the on-site mechanical technical lead at FusionWERX

- Own long-term knowledge of the tritium handling system, including maintenance and upgrades

- Support transition from build-out into operations

- Help define and eventually lead local mechanical staff as the facility scales

- Act as mechanical “glue” between operations, safety, facilities, and future projects

Qualifications and Skills:

- 8+ years of mechanical engineering experience

- Experience owning complex mechanical systems end-to-end

- Comfort working with subcontractors and vendors rather than doing all fabrication in-house

- Strong understanding of mechanical interfaces, requirements flow-down, and integration

- Ability to operate independently and make technical decisions with safety and schedule impact

- Project leadership experience and organization skills

Bonus Skills and Experience:

- Design and management of safety-critical gas systems

- Demonstrating regulatory compliance of gas systems

- Vacuum systems, gas handling, or hazardous materials

- On-site integration and commissioning experience

- Hands-on building experience

- Experience working with systems that generate radiation and radioactive material

- Forklift certification

Perks:

- Excellent medical, dental and vision benefits.

- 10 paid holidays and company-wide December holiday break.

- Generous paid vacation and sick time.

- Small, tight-knit team with low barriers to action.

- Exposure to a wide variety of problems for unparalleled, hands-on professional growth.

- Meaningful equity in the form of stock options.

We value people of all races, ethnicities, genders, ages, religions, and sexual orientations. We are an equal opportunity employer, and you do not need to match every listed qualification to apply. If you’re excited about building real systems and pushing fusion forward, we encourage you to apply.