About LPRINT

LPRINT is a French deep-tech startup, spun off from Inria and backed by X-Up (École Polytechnique). We're building an industrial 3D printer for printed circuit boards (PCBs) — giving hardware engineers the freedom to validate their designs as fast as software teams validate code.

Today, prototyping a PCB means fabbing it out, shipping it, and waiting weeks. We're changing that: our printer lets engineering teams manufacture industrial-grade PCBs directly on-site, with no fab and no lead time.

We're a small, hands-on team at an exciting stage — the kind of place where one engineer's work shows up in the product within weeks, not quarters.

The role

We're hiring our first Lead Opto-Mechanical Engineer to define and own the precision mechanics at the heart of our printer. There's no one ahead of you on this — you'll set the technical direction, standards, and practices for the discipline at LPRINT, and grow it as the company scales. You'll work closely with our electronics, and software engineers, owning mechanical sub-assemblies end-to-end — from concept to a working, debugged prototype on the bench.

Your missions:

• Own and define the opto-mechanical engineering approach at LPRINT
• Design and evolve the mechanical and opto-mechanical modules of our printer, in close collaboration with our optics, electronics, and laser systems engineers
• Design precision positioning mechanisms — linear drives, ball screws, linear guides, and the integration of linear/angular encoders
• Design opto-mechanical assemblies: kinematic optic mounts, alignment mechanisms, and vibration-resistant platforms
• Design thermal stabilization and cooling systems (air and liquid)
• Take a sub-assembly from concept through to a finished, working product, with limited supervision
• Assemble, align, and debug prototypes on the bench yourself — this is a hands-on role
• Maintain technical documentation, BOMs, and manage engineering change orders (ECOs) as the design evolves
• Design for manufacturability, keeping machining (milling, turning) and sheet metal fabrication in mind
• Help build our CE marking / Technical File compliance as the product matures

What you'll bring

Must-have:

• 5+ years of mechanical design experience with optoelectronic devices
• A track record of owning a mechanical sub-system end-to-end on a real industrial product, not just contributing to one
• Strong command of SolidWorks and Fusion 360
• Experience developing industrial equipment, machine tools, or industrial printers
• High-precision mechanical experience for additive manufacturing technologies (SLS, DED, or similar)
• Hands-on experience assembling, aligning, and debugging prototypes on the bench yourself
• Autonomy: you're comfortable owning a sub-assembly from concept to finished product with limited support
• A genuine taste for hands-on work — you're as happy at the bench as at the CAD screen
• Comfortable working in an R&D environment where requirements evolve quickly
• Professional English

Nice-to-have:

• Familiarity with European CE marking requirements and Technical File documentation under French/EU regulations
• Experience with materials suited to harsh environments and solvent exposure
• SolidWorks Simulation or ANSYS
• Experience documenting BOMs and managing ECOs in a regulated or quality-driven environment

Why join LPRINT

• The chance to build a discipline from zero at a deep-tech startup — you define how opto-mechanical engineering is done here, not inherit someone else's system
• A key role in the development of a genuinely disruptive industrial technology, at the crossroads of precision mechanics, optics, electronics, and additive manufacturing
• Real ownership and direct impact: what you design ends up in the machine, fast, working directly with the founders
• A small, international, hands-on founding team
• Meal vouchers (Tickets Restaurant)
• Access to one of the best-equipped fablabs in France, at the Drahi-X Novation Center, École Polytechnique — right where you'll be building
• Direct access to the École Polytechnique innovation ecosystem: labs, researchers, startups, gym, and events on campus

Recruitment process

1. A 30-minute introductory call with the founding team
2. A technical interview with the hiring manager, focused on your design and hands-on experience
3. A visit to our workshop to meet the team and walk through a real technical case
4. Offer

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