Senior AI Engineer

We’re on the lookout for an ambitious AI-Engineer to join our Engineering team at our office in Berlin. Join us in building the largest AI enabled fintech for healthcare!

What to expect in the role as Senior AI Engineer:

As part of our freshly launched AI division at Nelly, where you'll be one of the pioneers shaping our future in AI. In a small, agile team, you'll work on developing cutting-edge AI systems and robust data pipelines—from rapid prototypes to scalable production solutions. This role is ideal for someone who combines deep ML theory with practical cloud and data engineering know-how, and who can drive innovative GenAI initiatives while keeping a pragmatic product focus.

About Nelly

We are building the AI-Driven Financial Operating System for European healthcare, solving the biggest challenges for patients and practices. We create what no bank or software platform can handle. Our all-in-one platform transforms chaotic administrative processes into intelligent, automated workflows, from patient care to billing to next-generation payments. Because we truly believe: healthcare should be less about paperwork and more about people.

Why? Because Europe is facing a massive shortage of medical professionals. And if we don't rethink the way practices work, the system won't be able to keep up. With our Series B funding of over €50 million from world-class investors, we are turning our vision into reality.

What sets us apart: We work with the best team, which is why we give everything together every day. We believe in Talent Density, because exceptional people make everyone around them better. At Nelly, we move fast and expect everyone to keep up. Stagnation isn’t an option, which is why we invest heavily in growth. AI is an essential part of how we work at Nelly. We expect you to use it every day and give you everything you need to do so. You get trust and ownership and we expect you to speak up, even when it's uncomfortable.

What you'll bring:

• Technical leadership mindset with high agency and proactive drive—obsessed with building world-class systems and enabling teams to ship exceptional user experiences.
• 8+ years building and operating backend systems in production (strong Python skills required - ideal as well: TypeScript for integration work), with 3+ years shipping LLM/GenAI features to users (RAG, tool use, planning, agent frameworks e.g MCP, multi-agent systems).
• Strong ML fundamentals with hands-on experience in model evaluation, self-evolving agents (e.g Memory).
• Deep expertise in distributed systems design: API architecture, data modeling, high-throughput async systems, event-driven architectures, caching strategies, and performance optimization.
• Advanced retrieval engineering experience: embeddings, sophisticated chunking strategies, hybrid search algorithms, schema/metadata design, knowledge graphs, comprehensive eval frameworks, and production monitoring.
• Proven track record of technical leadership: driving architecture decisions, mentoring engineers, and establishing engineering best practices.
• Experience with cloud native development at scale, ideally AWS, but GCP is a strong plus, too.
• Excellent communication skills in English with ability to articulate complex technical concepts to diverse audiences.

Bonus skills:

• Experience with modern data workflow orchestration frameworks such as Dagster, Airflow, or Prefect, with emphasis on building robust, dependency-aware pipelines at scale.
• Track record of technical writing, open-source contributions, or speaking at industry events.
• Fluent German is a big plus, to improve the interaction between you and our user base.

What we offer:

• The people you get to work with. You will work alongside the brightest minds we could find, on hard problems, as a team. We take on challenges together and we never forget to have fun doing it.
• Room to grow faster than almost anywhere else. New challenges, more scope, real ownership from day one. We trust you to own it and to speak up when something is wrong. Just do not expect to stand still.
• A yearly learning and development budget, plus the coaching, feedback and internal knowledge that actually move you forward. Real investment in your learning.
• A front row seat while we build something big. We are building the financial operating system for European healthcare, with AI woven into how we build, sell and support. Real scope, real impact.
• Deutschlandticket or Swapfiets membership.
• Urban Sports Club membership.
• Flexible working hours and a hybrid setup and up to 4 weeks of workation.
• A dog friendly office.

We welcome applications from people of all genders and backgrounds, regardless of origin or age. If you're convinced you're the right fit for this role - even if your CV doesn't match the requirements 100% - tell us why.