Senior Thermo Mechanical Engineer

Amperesand; San Francisco (CA); On-site; USD 140,000 - 190,000; Full time

Benefits offered by this job

Medical benefits

Vision benefits

Dental benefits

401k plan

Paid time off

Parental leave

Job summary

Amperesand is seeking a Senior or Staff Thermo‑Mechanical Design Engineer to develop an advanced liquid‑cooling system for a next‑gen solid‑state power conversion platform. This hands‑on role covers architecture, sizing, CAD, CFD, and validation, with close collaboration across mechanical, electrical, manufacturing, and quality teams.

You’ll own thermal design, work with suppliers and factory teams, and tackle novel engineering challenges to push performance and manufacturability in a

Qualifications

• 3+ years for Senior level; 6+ years for Staff level.
• Bachelor’s in mechanical engineering or closely related field; advanced degrees a plus.
• Experience with liquid‑cooling thermal systems and CAE tools.
• Hands‑on testing and validation experience.

Responsibilities

• Develop the thermal system for the platform from architecture into mass production.
• Model thermal performance across operating conditions and mission profiles.
• Design CAD models and thermal components, including coolant routing and interconnections.
• Partner with manufacturing and quality teams on DFM/DFA to ensure manufacturability.
• Prototype and validate the thermal system; troubleshoot issues.

Skills

Thermal design

CAE analysis

Hands-on testing

Problem solving

Education

BS in Mechanical Engineering

Masters or PhD preferred

Tools

CATIA 3DX

Siemens Amesim

Job description

Company Overview

Amperesand is reinventing how the world powers its most critical systems. We are facing a once-in-a-generation opportunity for infrastructure disruption. Electricity demand is skyrocketing, driven by AI factories, electric vehicles, and modern industrial growth. Energy supply is shifting to incorporate a more diverse mix of resources – including solar, gas, and batteries – at a massive scale. And yet the power infrastructure behind our latest mega-projects hasn’t meaningfully changed in nearly 100 years. Supply chains for today’s infrastructure equipment can’t match the pace and sophistication of critical energy projects. Amperesand is building hardware and software that rewrites this broken power infrastructure playbook to support a new era of energy abundance. We’ve built a new class of intelligent, software‑defined power infrastructure products leveraging a decade of advanced medium voltage Solid State Transformer research that’s now ready for commercial deployment. Our products and solutions go far beyond the capabilities of traditional electrical equipment. We make power systems that are faster to deploy, dramatically smaller and more efficient, and capable of supporting modern, dynamic energy needs for tomorrow’s most demanding energy consumers. Scalable in‑house advanced manufacturing capability is our foundation for meeting timeline and quality expectation to serve infrastructure customers around the world. Amperesand is led by breakthrough energy hardware development veterans and funded by top tier investors who share our vision of building a category‑defining energy technology company. With hubs in San Francisco, Reno, and Singapore, our global team is laser focused on building foundational technology to solve the most pressing problems in power infrastructure at scale.

About Amperesand

Amperesand is building next‑generation power infrastructure systems for Data Centers, EV charging platforms, and future energy applications. Our systems combine advanced power electronics, embedded controls, and scalable energy architectures to rethink how power is converted, controlled, and deployed.

About The Role

Role Summary

Amperesand is looking for a Senior or Staff level Thermo‑Mechanical Design Engineer to develop an advanced liquid‑cooling system for its next‑generation medium‑voltage solid‑state power conversion platform. This is a hands‑on role where you’ll develop the thermal system through architecture and concept selection, system sizing and modeling, CAD and detailed design, thermal CFD simulation, coolant and airflow routing, design for manufacturing and assembly, thermal system validation, and troubleshooting. You’ll work closely with mechanical, electrical, manufacturing, quality, suppliers, and factory teams to design, develop, and build the best system for a novel application, solve problems that don’t have established answers, with the opportunity to own thermal design. Thermal performance is critical to the overall performance of our solid‑state power converter and a key differentiator for Amperesand. We are looking for someone with deep expertise in thermals, system modeling and simulation, detailed design experience, and a track record of complex technical work and solving novel problems. We are not looking for someone who simply executes to a defined specification. The role can be based in Reno, San Francisco, or the South Bay.

What You’ll Do

• Develop the thermal system for Amperesand’s solid‑state power conversion platform from architecture into mass‑production.
• Work on architecture and concept selection.
• Model the thermal system performance across our operating conditions and mission profiles.
• Detailed design of the thermal system components, including 3D and 2D CAD of structures, coolant routing, interconnections, and thermal CFD.
• Partner with the manufacturing and quality teams on DFM/DFA activities to ensure the thermal system design is manufacturable.
• Prototyping and validation of the thermal system.
• Problem solving anywhere and everywhere between architecture and start of production.

What You’ll Bring

• Years of experience: 3+ for Senior level, 6+ for Staff level
• BS in mechanical engineering or a closely related field, Masters or PhD are a plus
• Liquid‑cooling thermal system and mechanical design experience, CAE expertise
• Compressor‑loop refrigeration system experience
• Demonstrated ability to deliver a thermal system and solve novel engineering problems
• Hands‑on testing and validation experience

Nice to Have

• Experience with Catia 3DX
• Experience with Siemens Amesim or similar
• Familiarity with high‑voltage design

How We Work

• Employment Type: Full-time
• Location: San Francisco
• Work Model: Onsite
• Travel Requirements: Travel to the factory in Reno during builds will be required, ~20% for 1‑2mo/yr
• Onsite Collaboration Rationale: Given the highly collaborative and cross‑functional nature of hardware, embedded systems, and product development, in‑person partnership across engineering and product teams is critical to enabling rapid execution, technical alignment, and successful development outcomes.

Why Join Amperesand

• Work on next‑generation power infrastructure systems
• High ownership and visibility
• Cross‑functional collaboration
• Opportunity to shape future products and infrastructure
• Fast‑moving startup environment

Pay Disclosure & Benefits

Compensation will be determined based on experience, location, and other factors permitted by law.

The benefits outlined below apply exclusively to employees located in the United States:

• Competitive Salary + Incentive Stock Options
• Medical, vision, and dental benefits for employees and their dependents, effective from the start of hire
• Company paid Basic Life, AD&D, short‑term and long‑term disability insurance
• 401k retirement savings plan through Empower
• Employees receive paid time off (PTO), paid sick days, and paid company holidays
• Commuter Benefits
• 100% paid maternal leave (12 weeks) and paternal leave (6 weeks)

The benefits outlined below apply to employees located in Singapore:

• Competitive Salary + Incentive Stock Options
• Group medical, hospitalisation and surgical insurance, outpatient or GP coverage, group term life, dental and personal accident insurance
• Employer and employee Central Provident Fund contributions in accordance with the CPF Act (for Singapore Citizens and Permanent Residents)
• Annual leave, paid sick leave, hospitalisation leave, and all Singapore public holidays, in line with or exceeding the Employment Act
• Commuter Benefits
• Government‑paid maternity, paternity, shared parental, and childcare leave in accordance with prevailing Singapore statutory entitlements

Additional benefits may be available depending on the role and employment type. Benefits are subject to the terms of applicable company policies and plans.

Candidate Confidentiality & Information Protection

As part of our commitment to protecting confidential and proprietary information, candidates should not disclose or provide Amperesand with any confidential, proprietary, or trade secret information belonging to a current or former employer or any other third party during the application or interview process. Please do not submit or present employer‑owned source code, schematics, designs, technical documentation, internal presentations, customer information, prototypes, or other confidential materials. Candidates should discuss their experience and accomplishments at an appropriate level and use only information and materials they are authorized to share.

Equal Employment Opportunity

Amperesand is an equal opportunity employer and complies with all applicable federal, state, and local fair employment practices laws. All qualified applicants will receive consideration for employment without regard to race, color, religion, national origin, ancestry, sex, sexual orientation, gender, gender expression, gender identity, genetic information or characteristics, physical or mental disability, marital/domestic partner status, age, military/veteran status, medical condition, or any other characteristic protected by law. Amperesand is also committed to working with and providing reasonable accommodations to individuals with disabilities. Please let your recruiter know if you need an accommodation at any point during the interview process.