Senior Mechanical Design Engineer

  • 91370 Verrières-le-Buisson, France (PARIS)
  • International environment, French + Very good English
  • Space and Aviation manufacturing
  • Min 10 years of experience minimum
  • To be negociated

We are hiring on behalf of a start-up aiming to develop and commercialize a breakthrough space propulsion technology for small satellites.

The result of over 10 years of research and development within a cutting-edge laboratory, their technology offers exceptional performance and promises significant commercial potential. Their team of around twenty people has already conducted extensive testing on prototypes in our lab, confirming the disruptive nature of their system.


To support their development efforts, they are hiring an Experienced CAD Designer & Mechanical Architect for a permanent position. In a dynamic and innovative environment, you will play a key role in the design, modeling, and validation of the mechanical and thermal systems of our ion thrusters, working closely with the systems, electronics, AIT and R&D teams.

Beyond your technical expertise, you will act as a technical lead and expert for the Mechanical-Thermal team, currently composed of three engineers. You will guide them in their missions, provide technical advice, and oversee mechanical and thermal design and analysis activities.

Main responsibilities:

– Oversee design activities including CAD modeling and technical drawings for our systems and
subsystems
– Define the mechanical and thermal architecture of the thrusters (structure, interfaces,
thermal envelope, heat dissipation, etc.)
– Perform or supervise simulations (FEA, mechanical and thermal analyses)
– Select materials and technologies suitable for the space environment (vacuum, vibration,
thermal constraints)
– Manage manufacturing launch and follow-up with suppliers and machining partners
– Provide technical guidance to the mechanical/thermal team and supervise their work
– Act as the main technical contact and reference expert on mechanical and thermal topics
– Write technical documentation: justification notes, drawings, test reports
– Oversee prototyping, assembly, integration, and environmental testing phases
– Participate in technical reviews (PDR, CDR, TRR, etc.)

LOCATION
Position based in Palaiseau, France (91)

PROFILE REQUIRED
– Master’s degree or PhD in Mechanical, Thermal, or Aerospace Engineering
– 10+ years of proven experience in mechanical design, ideally in the space sector
– Proficiency with CAD tools (SolidWorks, CATIA) and simulation software (ANSYS, Abaqus, etc.)
– Good knowledge of ECSS/NASA standards and space environmental testing (thermal, vacuum,
vibration)
– Experience in thermal design and simulation is a plus
– Strong technical leadership, mentoring ability, autonomy 
– Experience in a start-up or agile environment is a plus

You are autonomous, rigorous, and pragmatic. You are a team player and enjoy contributing in a fast-
paced, entrepreneurial setting.

For more than ten years, I’ve been driven by one idea — the future of Space and Defense depends on the people behind it. My career began in technical recruitment, where I had the privilege to hire engineers designing cutting-edge systems for aerospace and advanced manufacturing.

Co-founding Demexios was a natural next step: a way to transform my industry knowledge and relationships into a dedicated structure that helps clients recruit faster, smarter, and with strategic alignment.
Over time, I built long-term partnerships with companies leading technological sovereignty — from NewSpace startups developing electric propulsion to defense integrators modernizing tactical and surveillance systems. These collaborations allowed me to form a powerful network of decision-makers, project leaders, and experts who now trust Demexios to deliver when precision truly matters.
Today, my role is not just to connect candidates and companies — it’s to ensure that every hire strengthens our clients projects.

I’ve built my career in sales and recruitment across several industries space, tech, healthcare, and defense. I’ve always been drawn to innovation and the talented people who turn ideas into reality. Over the years, I’ve learned how much a motivated and skilled team can define a company’s success and how the right people will shape the future of the New Space and defense industries.

My international background has allowed me to work with both startups and global organizations, helping them identify individuals who truly fit their culture and business goals. This combination of experience in technology and talent acquisition naturally led to the creation of Demexios.

At Demexios, our mission is simple: to connect experts with the companies that need their skills particularly in the defense and space sectors. I firmly believe that no ambitious project can succeed without a skilled and cohesive team driving it forward.

My commitment is to be a trusted partner for our clients, supporting them step by step in building strong, high-performing teams that deliver tangible results whether their ambitions lie on Earth or beyond.