Senior Software Engineer, Python

We’re on the lookout for an ambitious Senior Software Engineer with focus on Python to join our Engineering team at our office in Berlin. Join us in building the largest AI enabled fintech for healthcare! 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 to expect: 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 isn't a nice-to-have 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. JOINING US, YOU WILL - Build and maintain our Python backend using FastAPI, Pydantic, SQLModel/SQLAlchemy, and PostgreSQL (including pgvector), designing the APIs and data models that power the platform - Contribute across the stack when needed, working with our TypeScript, React, Next.js, and Node.js applications - Build AI-powered workflows using modern language models, orchestration frameworks, and evaluation tooling - Take ownership from development to production by building, deploying, and operating services on AWS with infrastructure managed through Terraform - Collaborate closely with product, design, and data to ship impactful, user-centric features - See your ideas go from concept to implementation, impacting customers within your first few days - Make a significant contribution to defining, maintaining and improving our architecture and best practices - Join a driven, highly skilled, engineering team and collaborate with talented professionals - learning from their expertise and contributing your own WHAT YOU'LL BRING - 5+ years of experience in software engineering - Strong proficiency in Python, ideally with a modern web framework like FastAPI (or Django/Flask) - Experience with data and API modeling (e.g., Pydantic, SQL/ORMs) and relational databases like PostgreSQL - Experience with cloud platforms like AWS and infrastructure as code (Terraform a plus) - Bonus: hands-on experience building with LLMs / AI agents in production - Knowledge of software engineering best practices for the full development life cycle - A pragmatic mindset and strong sense of ownership - Team player attitude with excellent communication skills WHAT WE OFFER - BVG ticket or a Swapfiets membership to cruise through the city - Urban Sports membership to sweat, stretch, or sauna your way through the week - Top of the line working equipment - Flexible hours and a hybrid setup in the heart of Berlin - Enjoy up to 4 weeks of workation wherever inspiration hits - A cozy, dog-friendly office where good vibes are basically mandatory - A fridge full of cold drinks and snacks waiting to be claimed We celebrate diversity and welcome individuals of all genders (m/f/d) to apply - and because we know confidence gaps and impostor syndrome can get in the way, please don’t hesitate even if you don’t meet every single criterion; if you’re exceptional, tell us why, and we’d genuinely love to hear from you.