Senior Data Engineer

Position: Senior Database Engineer Location: Kraków, Poland Working mode: Initially remote; once the Kraków office is ready, 3-4 days per week onsite

About our client Our client is an Israeli sports-tech company combining advanced data engineering, AI/ML and mathematical modelling to build high-performance real-time sports analytics solutions. The company processes large volumes of real-time data across sports including football, basketball, baseball and American football, transforming it into predictions and actionable insights. Its technology supports data-driven organizations operating in environments where speed, scalability and data accuracy are critical. The company is now building its new R&D team in Kraków, giving engineers the opportunity to join at an early stage and help shape the technical foundations of the new organization.

The Role

As a Senior Database Engineer, you will be responsible for designing, optimizing and scaling high-performance database infrastructure supporting millions of transactions and real-time data flows. You will work with transactional databases, document databases, Kafka-based streaming and analytical data lakes, with a strong focus on performance, reliability and data consistency. A key part of the role will be ensuring that financial and transactional data remains accurate under high concurrency and large-scale workloads. You will combine hands-on database engineering with automation, cloud infrastructure and close collaboration with the wider data and engineering teams.

Key Responsibilities

• Design efficient database schemas and low-latency data access patterns for a microservices environment.
• Analyze and optimize query performance, including indexing, execution plans and high-concurrency bottlenecks.
• Design and implement table partitioning, data retention and archival strategies for large transactional and time-series datasets.
• Move historical and less frequently accessed data to data lake solutions such as Snowflake and S3.
• Design and operate real-time Change Data Capture (CDC) pipelines using Kafka and Debezium.
• Monitor database health, performance and availability, including alerting and proactive identification of throughput or data consistency issues.
• Design and maintain database backup, recovery, encryption and access-control mechanisms in cloud environments.
• Build and maintain database CI/CD pipelines covering schema migrations, version control and automated deployments.
• Automate database operations, ETL workflows and data-quality/anomaly detection processes using Python or similar scripting languages.
• Work closely with engineering and data teams to improve the scalability and reliability of the overall platform.

What We're Looking For

• 5+ years of hands-on experience in Database Engineering, Database Administration or a similar role.
• Strong experience with large-scale relational databases, particularly PostgreSQL and/or MySQL, handling high transaction volumes.
• Experience working with high-scale document databases, particularly DocumentDB or similar technologies.
• Strong understanding of indexing strategies, query optimization, execution plans and transaction isolation levels.
• Practical experience with database partitioning and data retention/archival strategies.
• Experience operating cloud databases, particularly AWS RDS/Aurora or GCP Cloud SQL.
• Hands-on experience with real-time data streaming, CDC and Kafka, or high-volume ETL processes.
• Experience building and maintaining CI/CD pipelines for databases and schema migrations.
• Strong scripting/automation skills, preferably with Python.
• Ability to troubleshoot complex performance and scalability issues in high-concurrency environments.
• Strong English communication skills (C1); Polish is not required.
• Experience in fintech, iGaming or another highly regulated, transaction-heavy environment is a nice-to-have.

What We Offer

• Opportunity to join a new R&D organization in Kraków and help shape its technical foundations from the beginning.
• Primarily employment based on an employment contract (UoP), with B2B cooperation also planned as an option later.
• Initially fully remote work, followed by a hybrid model with 3-4 days per week from the Kraków office once the office is ready.
• Opportunity to work with high-volume transactional and real-time data systems serving millions of active users.
• International environment and collaboration with experienced technical teams and company leadership.
• Competitive compensation and the equipment required to perform the role.
• Opportunity to work on challenging problems around database scalability, data consistency, performance and real-time processing.