Location: Berlin (Full relocation required by 01.06.2026) Type: Full-time | Co-Founder role Start: 15 June 2026 You've spent years in engineering. You know how to build things that work in the real world – not just in simulation, not just on paper. You've probably had the itch to start something. But the right idea never came. Or the right team didn't exist. Or both. That's exactly who we're looking for. We are looking for a technical co-founder to join one of the hardtech startups currently applying to the Hardtech Innovation Accelerator at MotionLab.Berlin. These are ventures building physical products – think robotics, energy systems, advanced materials, medtech, or industrial hardware. Your co-founders have the domain expertise, the idea, and the drive. What they need is a technical co-builder who can own the engineering end-to-end. This is not a senior engineering position. You will co-own the company. You define the architecture, build the prototype, de-risk the core technology, and make the calls that determine whether the product works or doesn't. What you'll own: The full technical architecture: from component selection to system integration Building and iterating on a works-like prototype, hands-on, in the lab Turning engineering hypotheses into validated results Establishing and protecting the IP baseline of the venture Feeding market and customer signals back into your build decisions You have a degree or equivalent hands-on experience in mechanical engineering, mechatronics, electrical engineering, materials science, physics, or a related field. You've built something physical – a functional prototype, a research instrument, a piece of hardware that actually worked outside the lab. You are not looking for a job. You want to build something of your own and you're ready to commit to it fully. You are not looking for a job. You want to build one of the next great hardtech companies – and you're ready to commit fully to making that happen. What will set you apart: You've shipped a physical product, even in a university, research, or maker context You've worked across disciplines: hardware and firmware, mechanics and electronics, or similar combinations You've hit a ceiling somewhere – a research group, a corporate R&D team, a role that was never really yours to own – and you know it's time to change that The honest ask This is a full-time commitment. Not a side project. You will be relocating to or already living in Berlin, on-site from 15 June 2026 and will be building a deep tech venture side-by-side with your team members. You will be taking on founder risk: no fixed salary and the kind of uncertainty that comes with building something from scratch. When you join, you don't just get a co-founder. You get a launchpad. The startup you join is part of the Hardtech Innovation Accelerator at MotionLab.Berlin – which means instead of spending years figuring out the path from prototype to fundable company, you get 9 months of focused, structured acceleration to get there. What that means in practice: up to €200,000 in non-dilutive funding : €90k cash €110k in-kind. Zero equity taken from you and your team. €1M in on-site infrastructure : SLA/SLS/FDM 3D printing, 5-axis CNC milling, laser cutting, full custom PCB lab. Available 24/7. Expert support from day one : IP and patent law, financial controlling, legal setup, industrial design and 70 affiliate perks including AWS and HubSpot. Direct introductions to 60 DeepTech VCs : including HTGF and IBB Ventures. Demo Day, March 2027 : pitch to 400 people, including investors and corporate partners. You and your team keep 100% ownership. The programme takes 0% equity.