Senior Data Engineer - Freelance

Project Details

Location: Madrid, Spain

Work mode: Hybrid

Start date: 30 November 2026

Language(s): Fluent English and Spanish

Project Summary

We are looking for a Senior Data Engineer to propose, build and maintain data solutions, from ETL processes to the productionalization of models and the development of an MLOps framework. The role combines hands-on pipeline engineering with defining best practices and mentoring junior engineers. Candidates must submit a completed coding challenge together with their CV.

Main Responsibilities

Design, build and maintain robust ETL/ELT pipelines across various platforms

Implement and manage automation frameworks for data ingestion, transformation and reporting

Establish data governance best practices: lineage, documentation, security and compliance

Implement monitoring tools to ensure data quality and consistency across systems

Monitor and optimize the performance of data pipelines, databases and applications

Define best practices in testing, quality and data design, and mentor junior team members