Senior Backend Engineer

We’re on the lookout for an ambitious Senior Backend Engineer to join our Core data 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 Backend Engineer:

Core Data is responsible for providing data to product feature development and agent building teams across Nelly - effectively an MCP for the rest of the company. We own the ingestion pipelines, the canonical data model, and the tooling that lets product and AI teams build on top of clean, reliable data.

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

• Design and build ingestion pipelines that pull data from third-party PMS systems into Nelly's core data model.

• Own backend services in TypeScript/Node.js on AWS - event-driven, idempotent, observable.

• Evolve the canonical data model that every product team at Nelly builds on.

• Build the MCP servers and AI tooling that expose Core Data to internal agents and LLM-powered workflows - a chance to shape how AI ships at Nelly.

• Partner with product teams to triage and resolve ingestion issues by impact.

What you'll bring

• 8+ years backend-leaning experience, strong TypeScript/Node.js.

• Deep experience with data pipelines, ETL/ELT, and third-party integrations (queues, retries, idempotency, schema evolution).

• Strong data and API modeling - you've designed schemas that survived three product pivots.

• AWS in production.

• Bonus: healthcare/fintech data, event sourcing, MCP/LLM tooling experience.

What we offer

• BVG ticket or Swapfiets membership, so you get around the city fast

• Urban Sports Club membership, for sport and balance

• Flexible working hours and a hybrid setup

• Up to 4 weeks of workation

• A dog-friendly office with great vibes and a team that's fun to work with

• Snacks and a fridge full of cold drinks

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.