Senior Mechanical Engineer

Capella Space
Capella Space

Oxford, UK

Posted on Oct 5, 2026

About IonQ:

IonQ, Inc. [NYSE: IONQ] is the world’s leading quantum platform and merchant supplier - delivering integrated quantum solutions across computing, networking, sensing, and security. IonQ’s newest generation of quantum computers, the IonQ Tempo, is the latest in a line of cutting-edge systems that have been helping customers and partners including Amazon Web Services, and AstraZeneca achieve 20x performance results and accelerate innovation in drug discovery, materials science, financial modeling, logistics, cybersecurity, and defense. In 2025, the company achieved 99.99% two-qubit gate fidelity, setting a world record in quantum computing performance.

Headquartered in College Park, Maryland, IonQ has operations in California, Colorado, Massachusetts, Tennessee, Washington, Italy, South Korea, Sweden, Switzerland, Canada, and the United Kingdom. Our quantum computing services are available through all major cloud providers, while we also meet the needs of networking and sensing customers across land, sea, air, and space. IonQ is making quantum platforms more accessible and impactful than ever before.

Role

At Oxford Ionics, now part of IonQ, we are building the first practical quantum computer. Our systems are based on ion traps, which hold individual atomic ions tens of microns above the surface of a chip, and we design and build them in house, bringing together optomechanics, vacuum and cryogenic technology, electronics and system infrastructure.

We are looking for a Senior Mechanical Engineer to join our Systems team and take ownership of mechanical design from first requirements through to manufacture and integration. You will work on the hardware that surrounds the quantum processor, including cryostat requirements, cooling equipment, vacuum chambers and supporting structures, often in areas where the requirements are not yet fully defined.

Responsibilities:

You will work alongside scientists, technicians and the wider hardware design teams to bring new systems through to manufacture. That means producing CAD designs, bills of materials and assembly drawings, managing documentation in our PLM system and working with suppliers and our manufacturing team.

Our manufacturing team handles most assembly, but you will support technicians in the lab, investigate problems when they arise and make sure your designs can be built in practice. The work ranges from complex system layout to simple brackets and documentation, and you will see each piece through to completion.

Key responsibilities include:

  • Mechanically integrate multiple sub systems into one complete system, driving the overall mechanical layout.
  • Produce 3D designs of system assemblies and infrastructure, with detailed 2D drawings and bills of materials.
  • Design systems for vacuum pump down, gas handling and coolant management lines.
  • Plan the routing of cables, optical fibre and other physical services throughout the system.
  • Gather and scope requirements with scientists and engineers, then roll out upgrades and variations to system builds.

Requirements:

You will be a mechanical engineer with a strong design background and a practical understanding of how things are assembled and manufactured. A degree in Mechanical Engineering or a related field, or equivalent experience, and around five years of relevant industry experience will give you the grounding the role needs.

We want someone proactive who asks questions, gathers requirements, spots the missing details and sees a job through. You will be comfortable working independently with a high degree of autonomy, while collaborating closely with scientists and engineers across disciplines. Quantum experience is not required.

You’d be a great fit with:

  • Established CAD ability, ideally in SolidWorks, with a focus on assembly structure.
  • Experience of complex multidisciplinary systems and good assembly practice.
  • Experience with cryogenic or vacuum systems.
  • Familiarity with GD&T and preparing drawings for manufacture and inspection.
  • Experience of PLM systems or thermal analysis.

The total compensation package includes base salary, bonus, equity, and a range of benefits available on our career site.

Compensation will vary based on individual factors such as education, qualifications, and experience of the final candidate(s), specific office location, and calibration against relevant market data and internal team equity. Posted base salary figures are subject to change as new market data becomes available. Our benefits include comprehensive medical, dental, and vision plans, matching 401(k), unlimited PTO and paid holidays, parental/adoption leave, legal insurance, and a home technology stipend. Details of participation in these benefit plans will be provided when a candidate receives an offer of employment.

At IonQ, we believe in fair treatment, access, opportunity, and advancement for all while striving to identify and eliminate barriers. We empower employees to thrive by fostering a culture of autonomy, productivity, and respect. We are dedicated to creating an environment where individuals can feel welcomed, respected, supported, and valued.

We are committed to equity and justice. We welcome different voices and viewpoints and do not discriminate on the basis of race, religion, ancestry, physical and/or mental disability, medical condition, genetic information, marital status, sex, gender, gender identity, gender expression, transgender status, age, sexual orientation, military or veteran status, or any other basis protected by law. We are proud to be an Equal Employment Opportunity employer.

US Technical Jobs. The position you are applying for will require access to technology that is subject to U.S. export control and government contract restrictions. Employment with IonQ is contingent on either verifying “U.S. Person” (e.g., U.S. citizen, U.S. national, U.S. permanent resident, or lawfully admitted into the U.S. as a refugee or granted asylum) status for export controls and government contracts work, obtaining any necessary license, and/or confirming the availability of a license exception under U.S. export controls. Please note that in the absence of confirming you are a U.S. Person for export control and government contracts work purposes, IonQ may choose not to apply for a license or decline to use a license exception (if available) for you to access export-controlled technology that may require authorization, and similarly, you may not qualify for government contracts work that requires U.S. Persons, and IonQ may decline to proceed with your application on those bases alone. Accordingly, we will have some additional questions regarding your immigration status that will be used for export control and compliance purposes, and the answers will be reviewed by compliance personnel to ensure compliance with federal law.

US Non-Technical Jobs. Due to applicable export control laws and regulations, candidates must be a U.S. citizen or national, U.S. permanent resident (i.e., current Green Card holder), or lawfully admitted into the U.S. as a refugee or granted asylum. Accordingly, we will have some additional questions regarding your immigration status that will be used for export control and compliance purposes, and the answers will be reviewed by compliance personnel to ensure compliance with federal law.

If you are interested in being a part of our team and mission, we encourage you to apply!