---
title: 'Principal Mechanical Engineer, Structures at Sphere Defense'
canonical: 'https://feeny.ai/job/principal-mechanical-engineer-structures-sphere-defense-brussels-rftrtscct70f'
type: 'job'
last_seen: '2026-11-08'
---

# Principal Mechanical Engineer, Structures at Sphere Defense

- **Company:** Sphere Defense
- **Location:** Brussels, Belgium
- **Employment:** full-time
- **Work type:** onsite
- **Posted:** 2026-03-31
- **Last confirmed live:** 2026-11-08
- **Apply:** https://jobs.ashbyhq.com/sphere-defense/a5f1f142-7478-402f-9e7f-73f4aac48e3d

## Job description

## Who we are

Sphere Defense is a fully funded technology startup with the mission of providing allied countries with sovereign, effective and seamless autonomous countermeasures to neutralize todays’ and tomorrow’s aerial threats. Sphere Defense was founded by industry veterans with previous successful exits, and is headquartered in Brussels, Belgium, in the heart of Europe.

## About you

You are an experienced and highly-motivated Principal Mechanical Engineer, Structures that has worked with high-speed, small-scale flying vehicles (ideally fixed-wing drones). You are familiar with electro-mechanical systems, composite and common (metal, plastic resins) materials, aerodynamics, flight control surfaces and mid- to high- volume production. You also participated in bringing a mechanical product from 0 to 1 with considerable ownership.

## What you'll do

You will own the mechanical design of our countermeasure, define the manufacturing technologies and ensure a smooth transition from internal R&D to external production partners.

- Be one of the first members of a high-performing team, designing and developing autonomous countermeasures to protect allied countries from aerial threats
- Design, develop, prototype and test flying vehicles for flight performance, vibration resistance, reliability
- Calculate tolerances, stress and buffers to ensure the correct balance between cost, durability and performance
- Ensure DFM best practices before releasing drawings to vendors
- Identify the right materials and production techniques for different parts of the vehicles
- Identify and interface with external prototype and production partners
- Work closely with the electrical engineering team for E/M co-design
- Identify and work closely with simulation partners for FEA/CFD
- Ensure the designs adhere to the industrial quality standards by drafting test plans and working with test houses for validation and certification
- Draft production-level documentation, including GD&T, during the entire product lifecycle
- Implement rigorous design and review workflows to ensure the highest level of quality
- Be a team player and a mentor, being available to support and grow the team

Location: Onsite in Brussels, Belgium. Our office is close to Central Station. Reports to: Chief Technology Officer

## Requirements

- Bachelor’s or Master’s degree in Mechanical Engineering or equivalent
- At least 12 years in relevant roles, with increasing levels of ownership
- Demonstrated experience in the role, bringing products from conception to production with mid-volume production
- Deep experience with complex assemblies, with multiple mating parts
- Deep experience with TA over wide conditions
- Proficiency with SolidWorks or other established CAD packages
- Experience with composite materials and at least two among: plastic injection, thermoforming, metal stamping, machining (milling/turning)
- Experience with medium-scale, integrated electro-mechanical systems (actuators, sensors, flex circuits mechanical outlines, wiring harnesses, electrical connections, etc.)
- Experience in creating and maintaining production-ready documentation (technical drawings, assembly diagrams, etc.)
- Experience with PLM systems (Enovia, Windchill, etc.)
- Hands-on, with demonstrated ability in quickly prototyping mechanical systems
- Ability to execute incoming inspection and dimensional accuracy checks on golden samples

## Preferred Qualifications

- First-hand expertise with CFD and/or FEA
- Experience with creating CAM programs for manufacturing with CNC and lathe machines
- Experience with electro-optical systems
- Experience setting up in-house prototyping labs
- Experience tutoring operators for incoming quality inspection

## What we offer

- Attractive compensation
- Year-end bonus
- Stock Options Plan
- Mobility Budget
- 32 days of holidays
- Meal vouchers
- Private Health insurance

We are building a core team of hard-working people. If you want to join a company with tremendous impact and you are autonomous, creative and driven, we want to hear from you! Sphere Defense offers attractive compensation, stock options, and a unique opportunity to change the global defense landscape. This role is only open to candidates with right to work in Belgium. We cannot provide visa sponsorship at this time.

## About Sphere Defense

## Company Overview
- **One-liner**: Sphere Defense is a Brussels-based deeptech defense startup developing sovereign European counter-drone interceptors with AI-driven autonomous guidance, designed for kinetic interception of strike drones and point defense of critical infrastructure.
- **Entity Type**: Private (fully funded startup; funding rounds not disclosed)
- **Headquarters**: Brussels, Belgium
- **Founded**: 2025 (incorporated 3 December 2025)
- **Founders**: Not publicly named – described as drone industry veterans with international experience and previous successful exits.

## Core Business
- **Primary industry**: Defense / Aerospace & Defense / Counter-UAS (Counter-Unmanned Aerial Systems)
- **Target customers**: Allied governments, military forces, and operators of sensitive infrastructure (power plants, ports, airports, government/military sites)
- **Mission**: *“To keep allied countries safe with sovereign, effective and seamless countermeasures and protect them from aerial threats.”*

## Products & Services
- **Scalable Effector**: Kinetic intercept capability for strike drones. Point defense layer cued by third-party detection and C2, embedded into larger layered C-UAS architectures. Rapid setup, BVLOS interception.  
- **Jet-Powered Platform**: Multi-role interceptor with minimal footprint, maintenance-free operation, EW-hardened radio datalink, and AI-driven autonomous guidance.  
- **Embedded AI**: Multi-sensor fusion, autonomous last-mile target lock trained on millions of visual signatures, predictive targeting and guidance, human-AI teaming with flexible rules of engagement.  
- **Man-Portable Launch Base**: Autonomous deployment of interceptors with seamless logistics. SAPIENT-native, C2-agnostic, interoperable with existing defense infrastructure.

## Market Standing
- **Valuation**: Not disclosed (very early-stage, pre-revenue)
- **Key Metric**: Total funding not publicly disclosed – described as “fully funded” in recent job postings.
- **Notable Investors/Partners**: Not publicly named. Publicly debuted at BEDEX 2026 (Belgian defense industry exhibition). European procurement context includes Belgium engaging Origin Robotics, Anduril, COBBS, and Nokia for related programs.
- **Growth Signals**: Very recent incorporation (Dec 2025); already exhibiting at BEDEX 2026; active recruitment for core engineering team (Senior Robotics Software Engineer). Poised to benefit from surging EU demand for sovereign C-UAS capabilities.

## Competitive Advantages
- **EU-sovereign by design**: Engineered in Belgium, manufactured in Europe, EU-centric conflict-resilient supply chain. Money spent on defense stays in Europe.
- **Cost efficiency**: Claimed to be 200× cheaper per interceptor than the drones they target, making layered C-UAS economically sustainable.
- **AI-driven autonomy**: Embedded AI trained on millions of visual signatures, predictive guidance, and flexible human-AI teaming.
- **Architecture agnostic**: Acts as an effector layer cued by third-party detection and C2, easily integrated into existing layered C-UAS systems.

## Strategic Focus
- **Current priorities**: Build core engineering team; scale manufacturing in Europe; win initial contracts with allied defense ministries; establish supply chain sovereignty.
- **Direction**: Become the standard European kinetic counter-drone interceptor, expanding to additional platforms and AI capabilities.

## Why Work Here
- **Mission-driven impact**: Directly protect allies from the #1 cause of military casualties in Ukraine (drones cause >70% of casualties). Opportunity to shape the future of autonomous defense.
- **Early-stage ownership**: Be one of the first members of a high-performing team; shape software, perception architecture, and product direction.
- **Tech stack**: C++ for production, Python for prototypes, ROS2, simulation environments (Gazebo, Foxglove), PX4 flight controllers, Rust preferred. Work on autonomous flying vehicles, sensor fusion, VIO/SLAM, ML, reinforcement learning.
- **Compensation**: Attractive base pay plus stock options (depending on geography/position).
- **Location**: Onsite in Brussels, Belgium. Office at Rue d’Enghien 18, 1080 Brussels.
- **Culture**: High-ambiguity, self-starter environment; team of hard-working, autonomous, creative people. French or Dutch is a plus but English is primary.
- **Team size**: Very small (early-stage). Founder team includes industry veterans with previous successful exits.

## Sources
1. [Sphere Defense Official Website](https://www.sphere-df.com/)
2. [TechWiki Belgium Profile](https://techwiki.be/be/wiki/companies/sphere-defense)
3. [BEDEX 2026 Exhibitor Page](https://www.bedex.brussels/en/bedexexhibitors/details/sphere-defense~50f9e73a-2dea-f4ff-779e-3a1f1c9a0b08)
4. [Senior Robotics Software Engineer Job Posting (CareersInRobotics)](https://careersinrobotics.com/jobs/senior-robotics-software-engineer-defense-drones-iil)
5. [Sphere Defense Contact Page](https://www.sphere-df.com/contact)

## Other roles at Sphere Defense

- [Principal Machine Learning Engineer, Computer Vision](https://feeny.ai/job/principal-machine-learning-engineer-computer-vision-sphere-defense-brussels-d07y2apkqv4s) — Brussels, Belgium
- [Sr. Artificial Intelligence & Computer Vision Engineer, C-UAS](https://feeny.ai/job/sr-artificial-intelligence-computer-vision-engineer-c-uas-sphere-defense-86wntymdn29j) — Brussels, Belgium
- [CNC Programmeur en Verspaner](https://feeny.ai/job/cnc-programmeur-en-verspaner-sphere-defense-nivelles-dh9ht531e3an) — Nivelles, Belgium
- [Programmeur-Usineur CNC 5 axes (H/F/X)](https://feeny.ai/job/programmeur-usineur-cnc-5-axes-h-f-x-sphere-defense-nivelles-3f599sgce272) — Nivelles, Belgium
- [Test Engineer](https://feeny.ai/job/test-engineer-sphere-defense-brussels-c4yzy8bpd9yp) — Brussels, Belgium
- [CNC Programmer and Machinist](https://feeny.ai/job/cnc-programmer-and-machinist-sphere-defense-nivelles-pa6crg9bjnaz) — Nivelles, Belgium
- [Drone Lab Technician, C-UAS](https://feeny.ai/job/drone-lab-technician-c-uas-sphere-defense-brussels-p8r2e01jq9hn) — Brussels, Belgium
- [Drone Test Pilot & Tech, C-UAS](https://feeny.ai/job/drone-test-pilot-tech-c-uas-sphere-defense-brussels-enbdj9dgmsyq) — Brussels, Belgium
- [Senior Program Manager, Defense](https://feeny.ai/job/senior-program-manager-defense-sphere-defense-brussels-vrxe72jjwa8b) — Brussels, Belgium
- [Electronics Engineer](https://feeny.ai/job/electronics-engineer-sphere-defense-brussels-3vxk41b2z146) — Brussels, Belgium