The Role
We are looking for a Backend Engineer to join a small, high-ownership engineering team working on new product initiatives. You will be primarily focused on new product initiatives, building new services and features, though you may occasionally need to navigate existing codebases. You use AI coding tools as a core part of how you work, and you are excited about what that unlocks. You will own backend architecture decisions and work closely with product and data to ship reliable, high-performance services at scale.

This Is What You Will Do

Design, build and maintain backend services using Node.js

Work with large-scale data systems, including ClickHouse and other relational and non-relational databases

Build and maintain APIs that power our analytics product, working across real-time and historical datasets

Ensure services are performant, scalable, and maintainable

Contribute to architectural decisions for new product features

Work in an Agile environment with short, focused sprints

Collaborate closely with product, data and frontend teams

This Is You





5+ years of experience building backend services in production environments

Strong proficiency in Node.js and TypeScript

Solid experience with relational and non-relational databases (MySQL, MongoDB, ClickHouse or similar columnar databases)

Deep understanding of API design, data modeling, and web architecture

Strong focus on performance: you think about query efficiency, latency and scale by default

You use AI coding tools: Claude Code, Cursor, Copilot or similar, as a natural part of your development workflow, not as an afterthought

Experience with CI/CD pipelines and cloud deployments (Docker, GitHub Actions, Jenkins or similar)

You enjoy working on complex technical problems and take ownership of your solutions

Familiar with testing practices including unit, integration and end-to-end testing

We Will Be Impressed By Experience In

Experience with ClickHouse or other OLAP / columnar databas

📌 Backend Engineer (Madrid)
🏢 Marfeel
📍 Madrid