Data Platform Engineer

Job Title: Data Platform Engineer (Contract)Location: Remote in EUContract Type: Freelance / B2BStart Date: ASAPDuration: Initial contract until September 2026OverviewAn experienced Data Engineer is required to support the transformation of an existing proof-of-concept system into a scalable, production-ready platform. The current system is built as a monolithic Python script combining data ingestion, business logic, and UI components.The objective is to refactor and rebuild this into a modern architecture consisting of a FastAPI backend and React frontend (frontend handled separately).Key Responsibilities• Refactor a monolithic Python application into modular components (ETL, business logic, API layer)• Rebuild backend services using FastAPI, exposing clean and scalable REST endpoints• Preserve and validate existing business logic, including pricing calculations and margin rules• Integrate multiple data sources including Excel files (S3), SAP data via Snowflake, and manual cost inputs• Implement robust data processing and transformation pipelines• Contribute to improved data modelling aligned with internal standards where applicable• Apply best practices in software engineering including testing, version control, and code structureRequired Skills and Experience• Strong Python development experience, particularly with pandas and data transformation• Experience with FastAPI or similar REST API frameworks• Solid SQL skills and experience working with Snowflake• Proven ability to understand and refactor legacy codebases without loss of functionality• Experience with AWS services including S3, Lambda, API Gateway, and related tooling• Strong understanding of software engineering best practices (testing, modularisation, version control)Nice to Have• Experience with data modelling frameworks or structured data architecture approaches• Exposure to complex pricing or financial calculation systems• Familiarity with AWS CDK and broader AWS ecosystem