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

At IONOS, the leading European provider of cloud infrastructure, cloud services and hosting services, you will work together with a wide range of teams. We are characterized by open structures, a friendly working culture and flat hierarchies with a strong team spirit. We firmly believe that work and fun are compatible, and offer you the right environment for this. Our constant growth means that we are always looking for new colleagues. Become part of IONOS and grow with us.

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.

About IONOS

IONOS is the leading European digitalization partner for small and medium-sized businesses (SMB). The company serves around six million customers and operates across 18 markets in Europe and North America, with its services being accessible worldwide. With its Web Presence & Productivity portfolio, IONOS acts as a 'one-stop shop' for all digitalization needs: from domains and web hosting to classic website builders and do-it-yourself solutions, from e-commerce to online marketing tools. In addition, the company offers Cloud Solutions to enterprises who are looking to move to the cloud as their businesses evolve.

We value diversity and welcome all applications - regardless of, for example, gender, nationality, ethnic or social origin, religion, disability, age as well as sexual orientation and identity, physical characteristics, marital status or any other irrelevant factor subject to applicable law.