Senior Python Data Engineer - Freelance (M/F)

About the role

Daily rate (TJM): 550-600 The Analytics Factory of a major French retail player is the pillar of the company's data transformation, serving business teams (Marketing, Merchandise, Operations, E-commerce, Supply Chain, Financial Services). Within the AI Supply Chain team, you will contribute to the industrialization and optimization of data flows that power forecasting engines: store and warehouse sales forecasting, logistics load smoothing, supply optimization. You will join an agile team composed of Data Scientists, Data Translators, and Data Engineers, with the presence of a Tech Lead. MISSIONS & DELIVERABLES * Architecture & data pipelines: Design, develop, and maintain reliable, robust, and high-volume ingestion and transformation pipelines (sales, stocks, promotions, logistics data). * ML Industrialization & MLOps: Structure deployment environments and collaborate closely with Data Scientists to integrate demand forecasting models into automated and high-performance production pipelines. * Performance, observability & quality: Monitor data quality, freshness, and consistency, while optimizing costs and execution times on the cloud. * Governance & best practices: Apply the team's Definition of Done (automated tests, documentation, versioning) and contribute to the Data Engineering community. TOOLS & ENVIRONMENT Must Have * Mastery of advanced SQL and Python oriented towards data / engineering. * Confirmed practice of Google Cloud Platform for large-scale data orchestration and processing: BigQuery, Cloud Composer / Airflow, Cloud Storage. * Solid software engineering concepts: clean and modular code, version management with Git, automated tests (unit / integration), and containerization. Nice to Have * Development of robust and scalable applications with Python and its data (Pandas, NumPy) and web (Django, Flask, FastAPI, Requests) libraries. * Microservices and event-driven architectures. * Management of relational and document-oriented databases. * DevOps / CI-CD practices and observability principles (monitoring, diagnostic). * Craftsmanship: SOLID, YAGNI, test coverage (Sonar). * Participation in the entire software cycle, from design to run. * Ability to mentor, coach, and challenge a team of developers. * Agile methods, notably Scrum. * Master's degree (engineering school or university) in computer science, or equivalent experience. * More than 7 years of experience in Python Data Engineering. * Experience in the retail / mass distribution sector is a plus. * Clear communication in writing and orally, in French, for fluid exchanges with the business and teams.