Full-Stack Engineer - AI Platform

Do you want to make a change in the FitTech industry with an agile, fast-moving team? How about being part of the culture that truly values your opinions and ideas? If you want to develop software that really matters and deliver the best solutions for our clients alongside a like-minded team, then you're in the right place. Be part of the digital transformation of the fitness industry!

Join our high-velocity AI Speedboat team as a Full-Stack Engineer! We build AI-native products transforming fitness businesses across Europe, the US, and the UK. You’ll own end-to-end AI solutions—from backend services to user-facing interfaces—in a small, autonomous team shipping real products to real customers.

Your position in our team

• Backend (Java)

• Build and maintain Java services powering our AI platform, APIs, data pipelines, and ERP integrations

• Develop LLM orchestration, context management, and conversation state handling for our Nexus agent

• Implement authentication, rate limiting, cost optimization, and observability tooling

  
  

• Frontend (React / TypeScript)

• Build chat widgets, dashboards, and self-service tools for the AI agent

• Integrate AI features into Magicline interfaces for a seamless user experience

• Enable analytics, workflow builders, audience segmentation, and campaign tools

Your profile

• 5+ years building production web apps with strong backend (Java/Spring Boot) and frontend (React/TypeScript) skills

• Experience with real-time interfaces (WebSockets, SSE, polling) and modern state management (MobX, Redux)

• Comfortable with web fundamentals: HTTP, REST APIs, responsive design, and component libraries (MUI or similar)

• Skilled at writing automated tests and maintaining high code quality

• Strong collaboration skills; you thrive in cross-functional teams

• Fluent English (C1); German is a plus

  
  

Nice to have

• Exposure to AI/ML products, chat interfaces, or data visualization libraries (D3, Recharts)

• Knowledge of accessibility standards (WCAG), internationalization, B2B SaaS, ERP, or CRM

• Understanding of prompt engineering, agent frameworks, or AI observability

Your benefits with us

• Benefits package – private medical care and a sports card to support your health and well-being

• Flexible working hours – manage your schedule and enjoy a real work-life balance

• Flexible work model – work fully remotely or combine it with on-site collaboration at our modern office in Warsaw

• Flexible employment options – choose the type of contract that best suits your needs

• Access to Udemy Business – grow your skills with thousands of high-quality online courses

• Unique experience in the Fitness and SaaS industry – join a market-leading company in a dynamic, fast-growing field

• International team – collaborate with talented colleagues from around the world in a diverse and inclusive environment

• Unforgettable company events – take part in engaging team-building activities and memorable celebrations

• No dress code – express your personal style and feel comfortable at work