Senior Product Engineer (m/f/d)

About Ojin Ojin is The Human AI Company. We build the infrastructure that makes AI feel human. Our Human Agents deliver natural, lifelike conversations in real time, powered by our proprietary models and blazing-fast APIs on a globally distributed GPU fabric. We have delivered award-winning work with brands including BMW, H&M, and Clinique. Our new platform will define how the world experiences AI and we're assembling a small, ambitious team of exceptional people to do it. The Role As a Senior Product Engineer, you will not just write code, you will own products and features end-to-end. In the modern AI accelerated landscape, we believe a single high leverage engineer can drive impact comparable to entire teams of the past. You will be the bridge between technical implementation, product design, and user experience. We are looking for a builder who thrives in startup environments. You will work directly on Ojin, building everything from high-end interactive frontends to complex backend agentic systems. You won't just be handed a ticket; you will help define the solution, design the architecture, and ship it to users. This is a full-time position, either in our Berlin office or remote (CET +/- 2h). What You'll Do End-to-End Ownership: Drive features and projects from abstract concepts to production deployment. You will take ownership across UI/UX design, product logic, and technical implementation. Full-Stack Web Development: Architect and build our core web infrastructure