Back-end Engineer Java/Python – Data Platform

• Experience building and running production-grade back-end services
• Strong Java or Python skills (or a similar language), with a focus on clean, testable code
• Hands-on experience designing REST APIs, data models and schema evolution
• Solid SQL and relational database design skills (keys, constraints, indexing, transactions)
• Familiarity with NoSQL and graph databases (LPG/RDF)
• Understanding of versioning, idempotent processing, data lineage or data quality concepts
• Experience integrating external APIs and working with structured and unstructured data
• Practical knowledge of cloud services, CI/CD and observability
• Strong problem-solving skills and a collaborative mindset

• Prestigious position at one of the world’s largest banks
• Stable, long-term projects
• Competitive salary with a B2B contract
• Hybrid work (6 days per month from the office in Cracow)
• Private healthcare and multisport card
• Personal growth and development opportunities with the possibility to rotate between projects

,[Build back-end services and REST APIs for source registration, metadata retrieval and lifecycle management, Develop integrations with external sources, handling pagination, rate limits, errors and content changes, Design and evolve the metadata model (identifiers, versioning, content hashes, ownership, relationships), Create reliable data contracts and persistence layers with idempotent, safe reprocessing, Build reusable components for classification, enrichment, provenance, lineage and data quality, Add observability to services: status, latency, error classification, logs, metrics and traces, Integrate with the Knowledge Catalogue and the wider Knowledge Platform, Write unit, integration and contract tests, and contribute to CI/CD and production support, Work closely with the Technical Lead, architects and analysts to turn requirements into production-ready solutions] Requirements: Python, REST API, SQL, NoSQL, CI/CD, Java Additionally: Sport subscription, Training budget, Private healthcare, Free coffee, Gym, Bike parking, Playroom, Shower, Free snacks, Mobile phone, Free parking.