Mechanical Engineer

Lumai Limited; Oxford; On-site; GBP 70,000 - 90,000; Full time

Benefits offered by this job

Share option scheme

Pension scheme

Private health insurance

Cycle to work

L&D allowance

Subsidised on-site lunches

Holidays 25 days

Socials

Job summary

Lumai Limited in Oxford is seeking a skilled Mechanical / Optomechanical Engineer to join our team. You will design, analyse, and improve mechanical systems for our breakthrough optical compute product, collaborating with cross-functional teams and contributing to prototypes and testing.

We welcome both earlier-career and experienced engineers. The role offers a pathway to impactful work in a venture-backed startup with strong growth potential in the AI/optical space.

Qualifications

• Bachelor's or master's in mechanical engineering or related field.
• Minimum 2 years in mechanical design and analysis.
• Strong understanding of mechanical principles and materials science.
• Proficient in CAD software (SolidWorks/AutoCAD) and simulation (ANSYS).
• Able to work independently and with teams in a fast-paced environment.

Responsibilities

• Conceptualise, design, and develop compact optomechanical systems and mounting techniques.
• Collaborate with optical and electronics teams to produce prototypes.
• Use CAD to create detailed designs and drawings.
• Perform structural, material, and thermal analyses to optimise reliability.
• Participate in prototype builds, testing, and validation to meet specs.
• Manage multiple projects with deadlines and budgets.
• Coordinate with internal teams and external stakeholders on requirements.
• Monitor progress and implement mitigation strategies as needed.
• Prepare design specifications, technical reports, and documentation.

Skills

Communication

Mechanical fundamentals

CAD software

ANSYS

Teamwork

Education

Bachelor's or Master's in mechanical engineering

Related field

Tools

SolidWorks

AutoCAD

ANSYS

Job description

The Opportunity

Lumai is redefining how the world computes. We are an ambitious, venture-backed UK startup pioneering a breakthrough AI accelerator for data centres which uses 3D optical compute. Our radical technology uses light to perform computation at orders of magnitude faster speeds and at far greater scales than ever before, all whilst consuming far less energy than traditional approaches.

Lumai is unlocking performance and efficiency gains that could transform the economics of AI and compute infrastructure and reshape how intelligence scales globally.

If you are passionate about bringing groundbreaking technology to market, and want to be part of a team pushing the boundaries of what is physically possible, Lumai is where you can make it happen.

About Lumai

Founded in 2022, Lumai is a University of Oxford spin‑out using optical processing to accelerate large language models (LLMs) and other transformer‑based AI systems. The team combines expertise in optical computing, machine learning, and physics.

Lumai has already secured over $15 million in investment from leading deep‑tech investors like Constructor Capital, IP Group, PhotonVentures and government grants, and is scaling rapidly to deploy the fastest optical compute currently available globally.

The Role

We are seeking a skilled Mechanical / Optomechanical Engineer to join our Oxford‑based team. The ideal candidate will be responsible for designing, analysing, and improving mechanical systems and components for our product. The role involves collaborating with cross‑functional teams to develop innovative solutions that meet project objectives and industry standards. We welcome applicants both from earlier‑career and more experienced engineers.

What You’ll Do

Design and Development

• Conceptualise, design, and develop compact, robust optomechanical systems for products, prototypes and optical testing. Develop optical mounting and alignment techniques working with the optical team

• Work with the optical and electronics teams to produce system prototypes

• Utilise CAD software to create detailed designs and engineering drawings

• Conduct structural, material, and thermal analysis to optimise the performance and reliability of optomechanical systems

• Participate in prototype builds, testing, and validation of optomechanical systems to ensure compliance with design specifications and performance requirements

Project Management

• Manage multiple projects simultaneously, ensuring adherence to deadlines and budget allocation

• Coordinate with internal teams and external stakeholders to define project requirements and deliverables

• Monitor project progress, identify potential risks, and implement mitigation strategies as needed

Documentation and Reporting

• Prepare detailed documentation, including design specifications, technical reports, and project documentation

• Communicate project status updates, technical findings, and recommendations to key stakeholders

• Maintain accurate records of design iterations, test results, and project‑related documentation

What We’re Looking For

Must‑Have

• Effective communication and interpersonal skills

• Undergraduate or master’s degree in mechanical engineering or related field

• Minimum of 2 years of experience in mechanical design and analysis

• Strong understanding of mechanical principles, and materials science

• Proficiency in CAD software (e.g., SolidWorks, AutoCAD) and simulation tools (e.g., ANSYS)

• Ability to work independently and collaboratively in a fast‑paced environment

Strong Preference For

• Experience with optical products (e.g. projector, microscopes, Lidar, laser systems etc)

• Knowledge and practical experience of optomechanical system design

• Familiarity with the basic principles of optical design is desirable, but not essential

• Proficiency in structural simulation tools (e.g. ANSYS)

• Experience in taking technology from concept, to prototype, to product

Compensation & Benefits

• Highly Competitive Salary: We are not saying our salary is a blank check, but let's just say it won't be a source of your stress

• Share Option Scheme: We are all in this together! We believe in shared success while we build the Lumai of tomorrow

• Pension Scheme: Plan for retirement with AVIVA

• Private Health Insurance: We firmly believe that you come first, and a happy you is a healthy you! Look after yourself and your loved ones with AXA

• Cycle to Work: Spread the cost of a bike, a bike and accessories or just accessories and save on tax

• L&D Allowance: Stay at the forefront of your field with a £500 annual development budget

• Subsidised On‑site Lunches: Enjoy on‑site healthy meals at half the price, as Lumai covers 50% of the cost

• Holidays: Enjoy some deserved "me time" with 25 days paid holiday (plus bank holidays) per year

• Socials: Be part of an inclusive community enjoying occasional all‑company off‑sites, lunches and socials

Interview Process

Our process is four stages. An initial conversation with our HR team to understand what you want from the role and what we want from it. Two technical sessions with various members of our engineering team. Finally, an HR‑team session covering scope, terms, and any final questions. We aim to move fast on candidates we are excited about; expect roughly three to four weeks end to end.

Lumai is an equal opportunity employer. We make hiring decisions on merit, scope‑fit, and the strength of the working relationship we expect to build with each hire. Applications welcome from candidates of any background. If you are not sure whether you are a fit, send a note anyway.