Senior Data Engineer - Customer Identity Pipeline

About the role

A multi-award-winning software development team of over 100 engineers, designers and analysts, based in Leicester with hubs in Ukraine and Spain, is looking for a Senior Data Engineer for its Business Intelligence and Data Engineering team. The client is Europe's leading platform for buying and selling books, CDs, movies, games and fashion. You will own the end-to-end pipeline that creates the unified customer identifier across the businesses, working with Data Engineers and Business Analysts to build reliable, scalable and trustworthy customer identity data.

Key responsibilities

• Own the end-to-end pipeline that creates the unified customer identifier across Books, Media and Fashion
• Maintain and evolve the customer identity master data with a focus on accuracy, reliability and production quality
• Improve the probabilistic identity resolution model so matching decisions are measurable, transparent and explainable
• Build scalable, cost-efficient data pipelines across BigQuery, GCS and Cloud Run Jobs
• Add diagnostics, monitoring and structured validation for every model change, and fix edge cases in matching logic before they reach production
• Work with business and technical stakeholders to turn complex matching challenges into robust data solutions

Required profile

• 5+ years of experience in production data engineering
• Strong Python skills for production-grade data engineering
• Strong understanding of data quality, matching logic and precision/recall trade-offs
• Careful, structured, ownership-driven approach and clear communication of technical decisions
• English level B2 (independent user)
• Right to work in Spain (NIE and SS.SS.); the role is remote within Spain only, and relocation or visa support is not offered

Required skills

• BigQuery and advanced SQL in large-scale analytical environments
• Solid Airflow experience and reliable orchestration patterns
• Incremental pipelines and idempotent data processing
• Probabilistic record linkage or entity resolution in production
• Nice to have: Splink, Cloud Run Jobs, GCS, Pub/Sub, Parquet/Avro, dbt, downstream BI use cases, e-commerce or marketplace experience

What we offer

• Flexible and hybrid working
• Private medical healthcare insurance
• Training budget and extra holidays
• Professional development and knowledge sharing