Data Engineer (Python & Kafka) in Development Romania Access & Business Intelligence team (hybrid)

The position is in the Enterprise Business Intelligence Department (Romanian team), responsible for developing company-wide solutions for measuring, evaluating, and managing operational and strategic business objectives, part of our sister’s companies in Germany, 1&1 Telecommunications SE.

Main responsibilities:

• Design, develop, and maintain data pipelines and ETL processes using MS SQL Server, and Python, ensuring reliable data movement from source systems to the data warehouse and analytical layers.
• Build and operate real-time and near-real-time data ingestion pipelines using Apache Kafka — designing topics, building producers and consumers, and managing stream processing workflows.
• Develop and optimize stored procedures, views, and data transformation logic for both backend processing and frontend consumption (SSAS, Power BI).
• Write and maintain Python-based data services and integrations, leveraging libraries such as sqlalchemy, pyodbc, confluent_kafka, json, and FastAPI to connect, transform, and expose data across systems.
• Perform requirements analysis and effort estimation within projects and implement solutions as part of an international, cross-functional team.
• Collaborate closely with BI analysts and architects to translate business requirements into robust, scalable data solutions.
• Support Business Analysts with ad-hoc analyses on large data volumes, complex data models, and data extraction from operational systems.
• Design, code, test, debug, document, and support all types of data flows and transformation procedures consistent with established specifications and business requirements to deliver maximum business value.
• Support, enhance, and modify existing applications, pipelines, and codebases.

What we're looking for:

Core skills:

• Well-rounded knowledge of data warehousing and Business Intelligence concepts, including physical data modeling techniques specific to data warehouse requirements.
• Strong experience with MS SQL Server — database implementation, performance tuning, and writing efficient queries on large data volumes.
• Solid Python programming skills, with hands-on experience building data pipelines, REST APIs, and integration scripts using libraries such as sqlalchemy, pyodbc, confluent_kafka, json, and FastAPI.
• Experience with Apache Kafka — designing and managing topics, building producers and consumers, and working with Kafka Streams or similar stream-processing patterns.
• Ability to collaborate effectively with team members and cross-functional stakeholders in an international environment.

Nice to have:

• Mastery of SQL on large data volumes (complex joins, window functions, query optimization).
• Experience building and exposing REST APIs for data services (FastAPI or similar frameworks).
• Previous working experience in telecommunications (4G/5G).
• Familiarity with Microsoft BI tools (SSAS, Power BI).
• Experience with event-driven architectures and message queue patterns beyond Kafka.

What we offer:

• Access to local/international trainings, development and growth opportunities, including access to e-learning platforms, covering both technical and soft skills areas;
• Modern technologies, product responsibility;
• Flexible work schedule;
• Hybrid work option;
• Medical services package from one of two private providers;
• 25 vacation days per year;
• Substitute days off for public holidays that occur on the weekend;
• Meal tickets;
• Internal referral program;
• Team events, networking events organized to promote a passionate, creative and diverse culture;
• Summerfest and Winterfest parties;
• Of course, coffee, soft drinks and fresh fruits are on us in the office.