Staff AI Engineer

We celebrate diversity and encourage individuals of all genders (m/f/d) to apply. We’re on the lookout for an ambitious Staff AI Engineer to join our Engineering team at our office in Berlin. Join us in building AI products for medical practices - tackling manual processes, bureaucracy, & administrative overload so doctors and staff can focus on patient care instead of paperwork. As a Staff AI Engineer, you will play a critical role in shaping Nelly’s engineering strategy and architecture for our AI products. About Nelly We are a Tech Company and we believe healthcare should feel a lot less like paperwork… and a lot more like people. So we’re building the technology that lets medical practices run smoothly, simply, and without all the admin chaos that slows everyone down. Our platform turns messy processes into smart, automated workflows, from patient journeys to billing to next-generation payments. Powered by AI, built for real humans, and designed to give medical teams the time and headspace they desperately need. Why? Because Europe is facing a massive shortage of medical assistants. And if we don’t rethink how practices operate, the system won’t be able to keep up. We’re here to fix that, not with band-aids, but with real transformation. We’re backed by €50M in Series B funding from world-class investors and are scaling fast to build Europe’s leading healthcare fintech. Our vision: empower over a million medical practices and make life better for millions of patients. But here's the part we’re proudest of: we only work with nice people. It’s our number-one rule. No egos, no drama, no jerks. Just kind, curious, hardworking humans building something meaningful together. If that sounds like your kind of place — welcome to Nelly. JOINING US, YOU WILL - Embrace a fast-paced, agile environment where outcome and quick progress is achieved through experimentation and rapid iteration. - Define and drive AI strategy across multiple teams and engineering-wide initiatives. - Architect and lead the development of backend-first agentic products - Drive technical discovery, exploring and evaluating emerging AI technologies, building POCs for new products and ideas and turning them into real products - Lead cultural changes and set the standard for engineering impact, speed, and quality - Remain hands-on - whether writing foundational code, leading design reviews, or refactoring key systems - Define and champion engineering excellence - Mentor engineers - both AI engineers and other developers interested building AI products. be a trusted advisor to leadership. WHAT YOU WILL BRING - A technical leader (typically 8+ years of experience) with a track record of multi-team or org-level impact - An impact focused mindset - Experienced in enterprise-scale systems and multi-team architecture leadership - Technical leadership mindset with high agency and an impact focus who can provide strategic vision and dive deep into the technical details - Experience designing, building, scaling, and maintaining backend systems in production - Experience exploring, evaluating, and experimenting on, AI/ML based products in production - Experience with the challenge of building GenAI based products, such as creating guardrails and online evaluation to create a reliable ,secure, and safe system. - Strong AI/ML fundamentals with hands-on experience in model evaluation, AB testing, and monitoring stochastic systems - Excellent communication skills in English with ability to articulate complex technical concepts to diverse audiences. Joining us, you will - embrace a fast-paced, agile environment where outcome and quick progress is achieved through experimentation and rapid iteration. - architect and lead the development of backend-first agentic services combining LLM services with tool use/retrieval, ReAct and Knowledge Graphs - defining technical strategy, standards, and best practices across the AI division. - design and evolve our retrieval & knowledge infrastr