Senior Mechanical Design Engineer at PsiQuantum in Milpitas, CA

PsiQuantum's mission is to build the first useful quantum computers: machines capable of delivering the breakthroughs the field has long promised. Since our founding in 2016, our singular focus has been to build and deploy million-qubit, fault-tolerant quantum systems.

Quantum computers harness the laws of quantum mechanics to solve problems that even the most advanced supercomputers or AI systems will never reach. Their impact will span energy, pharmaceuticals, finance, agriculture, transportation, materials, and other foundational industries.

Our architecture and approach is based on silicon photonics. By leveraging the advanced semiconductor manufacturing industry, including partners like GlobalFoundries, we use the same high-volume processes that already produce billions of chips for telecom and consumer electronics. Photonics offers natural advantages for scale: photons don't feel heat, are immune to electromagnetic interference, and integrate with existing cryogenic cooling and standard fiber-optic infrastructure.

That approach has since been tested at the highest level of scrutiny the U.S. government applies to emerging technology, and it has held up. In 2025, PsiQuantum closed a $1 billion funding round that valued the company at $7 billion. In 2026, the U.S. Department of Commerce signed a $100 million Letter of Intent under the CHIPS and Science Act, followed by a $125 million agreement with DARPA under Stage C of its Quantum Benchmarking Initiative, PsiQuantum's most valuable U.S. government agreement to date. This year, we also broke ground on our utility-scale quantum computer in Brisbane, Australia, and continued building out our Chicago site. Victor Peng, our CEO, and co-founder Jeremy O'Brien, now Executive Chairman, lead a team and board that reflects how seriously the world is taking this build, joined this year by Intel's Lip-Bu Tan and Atomico's Niklas Zennström.

PsiQuantum also develops the algorithms and software needed to make these systems commercially valuable. Our application, software, and industry teams work directly with leading Fortune 500 companies, including Airbus, Lockheed Martin, Mercedes-Benz, Boehringer Ingelheim, and Mitsubishi Chemical, to prepare quantum solutions for real-world impact.

Quantum computing is not an extension of classical computing. It represents a fundamental shift, and a path to mastering challenges that cannot be solved any other way. The potential is enormous, and we now have the funding, the government validation, and the sites under construction to make it real.

Job Summary:

The Senior Mechanical Design Engineer is responsible for designing highly complex, cutting-edge optomechanical and optoelectronic subsystem assemblies. You will work closely with teams across a wide range of disciplines, including cryogenics, optics, electronics, and manufacturing. You will be expected to apply Design for Manufacturability (DFM) principles on a daily basis. Strong design skills incorporating mechanics of materials, thermodynamics, electronics, and precision design principles are essential.

This role offers the opportunity to apply your talents, make a meaningful impact, and learn about breakthrough technologies. You will work in a fast-paced, dynamic, and high-energy environment alongside a fun, talented, and highly collaborative team.

Responsibilities:

• Translate high-level, ambiguous requirements into practical design solutions.
• Collaborate with stakeholders to iterate and refine concepts, negotiate requirements in support of overall project goals.
• Rapid prototype concepts to iterate designs.
• Ownership of designs from prototype to production.
• Generate and maintain process flow documentation.
• Conduct DFMEA, PFMEA & risk analysis heat maps.
• Generate & maintain BOM’s & build standards.
• Ability to execute basic structural and thermal analyses to down-select designs.
• Practicing proper engineering revision control, preferably with Solidwork PDM / Arena (PLM), or NX.

Experience/Qualifications:

• Experience designing mechanical assemblies for optoelectronic devices, such as optical transceivers, co-packaged optics, and datacenter switching systems.
• Expertise in Design for Manufacturability, Design for Assembly.
• Expertise with GD&T.
• Expertise with tolerance analysis methods.
• Strong communication and interpersonal skills.
• Ability to quickly learn and apply new technologies and design principles in emerging or unfamiliar fields.
• Willingness to support colleagues in achieving team objectives.
• Demonstrated independent judgment.
• Continuous learning mindset.
• Proven ability to execute deliverables against schedule and quality targets.
• Bachelor’s degree or higher in Mechanical Engineering or a relevant discipline.
• 2–5 years of experience, with a focus on optomechanical design and/or optoelectronic packaging.
• Experience designing systems for cryogenic and vacuum environments is a plus.
• Experience with fiber optical industry is a plus.
• Experience designing semiconductor-related optomechanical assemblies, particularly for vacuum environments or applications sensitive to temperature-induced drift, is a plus.

PsiQuantum provides equal employment opportunity for all applicants and employees. PsiQuantum does not unlawfully discriminate on the basis of race, color, religion, sex (including pregnancy, childbirth, or related medical conditions), gender identity, gender expression, national origin, ancestry, citizenship, age, physical or mental disability, military or veteran status, marital status, domestic partner status, sexual orientation, genetic information, or any other basis protected by applicable laws.

Note: PsiQuantum will only reach out to you using an official PsiQuantum email address and will never ask you for bank account information as part of the interview process. Please report any suspicious activity to recruiting@psiquantum.com .

We are not accepting unsolicited resumes from employment agencies.

Base pay is one part of the total compensation package. Full-time roles are eligible for equity and benefits. Our compensation ranges reflect the cost of labor across multiple U.S. geographic markets, and we pay based on defined geographic zones. This position may be filled within one of the following U.S. geographic zones, each with its own salary range.

Actual compensation may vary outside of these ranges and is dependent on various factors including, but not limited to, a candidate's qualifications, relevant education and training, competencies, experience, geographic location, business needs, and internal equity. Your recruiter can share more details about the salary range applicable to your location during the hiring process.

• Zone 1 - Bay Area and NYC

• Zone 2 - Examples include Los Angeles and Washington DC

• Zone 3 - Examples include Austin, Chicago, and Sacramento

• Zone 4 - Examples include Nashville and Phoenix/Tempe and many remote locations

This position includes the following benefits: competitive health coverage for you and your dependents, 401(k) with company match, equity grants, access to financial wellness tools and planning resources, wellness benefits, family support programs, life and disability insurance, paid leave programs, company-designated paid holidays, discretionary time off (DTO), and an end-of-year company shutdown. Some of these benefits have eligibility requirements and may vary based on location, role, or employment status. Many of these benefits are subsidized or fully paid for by the company.

The estimated annual base salary range for this role is:

Zone 1

$167,800—$197,200 USD

Zone 2

$151,100—$177,500 USD

Zone 3

$134,300—$157,800 USD

Zone 4

$117,500—$138,000 USD