Senior Backend Engineer

About the role

Join the Core Data team as a Senior Backend Engineer to build ingestion pipelines and backend services that power Nelly's AI-enabled fintech platform for healthcare. Core Data is responsible for providing clean, reliable data to product feature development and agent building teams across the company.

What you'll do

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

What you'll need

• 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.

Nice to have

• Healthcare/fintech data, event sourcing, MCP/LLM tooling experience.

What they offer

• BVG ticket or Swapfiets membership
• Urban Sports membership
• Top of the line working equipment
• Flexible hours and hybrid setup in Berlin
• Up to 4 weeks of workation
• Dog-friendly office with snacks and drinks