Data Engineer (m/w/d)

About 1&1

1&1 is one of the leading telecommunications providers in Germany with over 3,100 employees and almost 16 million customer contracts. With pioneering spirit, unusual ideas and creative teams, we have conquered a leading market position in mobile communications and broadband connections. By combining the 1&1 fiber optic network, which is over 67,000 km long, and regional networks, we are creating Germany's most extensive fiber optic network. We are also building Europe's most modern 5G network based on the novel Open-RAN technology. With open interfaces and 5G functions in a powerful cloud infrastructure.

Write the 1&1 success story by shaping the future through the use and development of innovative technologies. Become part of 1&1.

Your Role

In this role, you will actively shape the transformation of our data landscape towards a modern, scalable Lakehouse architecture on Databricks. You will create the foundation for data-driven decisions and innovative AI use cases.

Responsibilities

• Design, development and operation of modern ETL/ELT pipelines based on Python (e.g. PySpark) in Databricks
• Replacement of existing data warehouse and ETL structures (MS SQL Server, Stored Procedures, Automic) with scalable Lakehouse architectures
• Setup of differentiated pipeline logics to ensure stability, SLA compliance and auditability
• Implementation of data quality checks (validation, reconciliation, quality checks)
• Ensuring data consistency during the migration of existing systems
• Implementation of transformations, schema mappings and metadata enrichment according to the target architecture
• Optimization of data pipelines regarding performance, costs and scalability
• Use of modern Databricks functionalities (e.g. Delta Lake, Structured Streaming)
• Monitoring of pipeline runtimes, resource utilization and system stability
• Close collaboration with BI, Analytics, Architecture and Development teams as well as business departments
• Creation and maintenance of technical documentation as well as ensuring traceability and governance

Qualifications

• Completed degree (e.g. Computer Science, Data Engineering, Business Informatics or comparable)
• Several years of experience (approx. 3-6 years) in Data Engineering
• Very good Python skills (esp. PySpark) and sound experience with Apache Spark and ideally Databricks
• Strong understanding of ETL/ELT processes, data modeling and pipeline orchestration
• Experience with Microsoft SQL Server and very good SQL skills
• Analytical, structured and solution-oriented way of working
• Experience with Databricks Lakehouse, Delta Lake and Structured Streaming
• Knowledge of orchestration tools (e.g. Airflow, Databricks Workflows)
• Understanding of Data Governance, Compliance and Metadata Management

Benefits

• Attractive salary
• Strong community of team players
• Trust-based working hours with flexible scheduling and the possibility of up to 40% mobile work
• Numerous further training opportunities on- and offline
• Discounts on 1&1 products and for various leisure activities
• Company-owned restaurant
• Free drinks and fresh fruit
• Job bike subsidy