Mechanical Engineer (Hardware Tooling) at Harmattan AI (Paris, France)Mechanical Engineer (Hardware Tooling)

Harmattan AI is a next-generation defense prime building autonomous and scalable defense systems. Following the close of a $200M Series B, valuing the company at $1.4 billion, we are expanding our teams and capabilities to deliver mission-critical systems to allied forces.

Our work is guided by clear values: building technologies with real-world impact, pursuing excellence in everything we do, setting ambitious goals, and taking on the hardest technical challenges. We operate in a demanding environment where rigor, ownership, and execution are expected.

As a Mechanical Engineer on Harmattan AI's R&D Hardware Tooling team, you will design and build the internal lab fixtures, jigs, rigs, and bench structures that help our engineering teams develop and validate products faster. You will own the mechanical side of tooling end-to-end: from bench and lab fixtures to environmental validation rigs, instrument enclosures, and RF/antenna characterisation mechanics. Unlike product design optimised for mass production, tooling mechanics here prioritise precision, repeatability over many cycles, and fast in-house fabrication. You will work at the intersection of mechanics, electronics, and development across every Harmattan hardware program.

• Design fixtures, jigs, enclosures, and bench structures in SolidWorks with full integration of electronics and instrumentation, maintaining complete 2D drawings with GD&T to guarantee fixture precision and repeatability.
• Design clamping, alignment, and actuation mechanisms — manual and pneumatic — for repeatable, ergonomic positioning of prototypes during bring-up and characterisation.
• Build fixtures rapidly in-house (3D printing, CNC, aluminium framing) and via quick-turn suppliers; iterate fast based on hands-on validation with the tooling hardware and software engineers.
• Own the development of bench and lab fixtures, environmental and reliability validation rigs, instrument/DAQ enclosures, RF/antenna characterisation mechanics, and modular bench structures for the R&D teams.
• Validate fixture repeatability, durability over many cycles, and operator ergonomics; use basic FEA and thermal/CFD where required (e.g. environmental rigs) to confirm designs.
• Manage quick-turn machining and printing suppliers; specify framing hardware and drive procurement with Supply Chain.
• Define and maintain a modular, reusable fixture-mechanics standard across product teams, directly reducing bring-up time and improving characterisation repeatability.
• Maintain fixture designs, drawings, build instructions, and maintenance records as the single source of truth for the team.

• Engineering degree in Mechanical Engineering, Mechatronics, Consumer Electronics, or equivalent.
• Proven experience designing lab or development fixtures, jigs, or rigs — or a track record of shipping physical products with a desire to build the tools behind them.
• Proficiency in SolidWorks, including complex assembly modelling and 2D drawings with GD&T.
• Hands-on experience with rapid prototyping and in-house fabrication (3D printing, CNC, off-the-shelf framing systems).
• Ability to integrate electronics and instrumentation into fixtures and enclosures with reliable measurement access.
• Strong instinct for tolerancing, repeatability, and fixture accuracy; comfortable working to tight positional constraints.
• Experience with mechanism and actuation design (clamping, alignment, pneumatic) is a strong plus.
• Basic FEA and thermal/CFD to validate designs is a nice-to-have.
• Appetite for ownership and fast iteration — a maker who gets hands dirty, works independently, and thrives in a small team without heavy process.

We look forward to hearing how you can help shape the future of autonomous defense systems at Harmattan AI.