Full Stack Engineer

About the role

NUMBERO, a German tech startup focused on after‑sales solutions for car dealerships, is expanding its Valencia development hub. We are looking for a versatile Full Stack Engineer who can own end‑to‑end feature development, from database design to frontend delivery and production monitoring.

Key responsibilities

• Develop and maintain web application features using React, TypeScript, Express.js and Node.js.
• Design database schemas, write migrations and optimise queries in MySQL/MariaDB.
• Build and expose REST APIs and integrate them with frontend components.
• Implement background job processing, scheduled tasks and asynchronous workflows (e.g., BullMQ).
• Contribute to AI‑driven features, LLM integrations and prompt engineering.
• Connect web applications with data platforms such as Databricks, Azure Data Lake Storage and PowerBI.
• Ensure code quality, high test coverage and conduct code reviews.
• Monitor, debug and maintain production systems independently.

Required profile

• Strong experience in full‑stack development with a focus on both backend and data engineering.
• Comfortable taking ownership of features from conception through deployment and monitoring.
• Ability to work collaboratively with technical and business stakeholders in an agile environment.
• Self‑motivated, proactive problem‑solver with a passion for automotive tech innovation.

Required skills

• React
• TypeScript
• HTML5
• CSS3 (Bootstrap, Tailwind CSS)
• REST API design
• Git
• Node.js
• Express.js
• MySQL / MariaDB
• Redis
• BullMQ (or similar queue system)
• Docker & Docker Compose
• JWT authentication
• Role‑based access control
• Cron job scheduling
• Databricks
• Azure Data Lake Storage
• PowerBI
• Azure cloud fundamentals