Senior Python Developer | Wroclaw

Senior Python DeveloperLocation: Wrocław, PolandWork Model: Hybrid – 3 days per week in the Wrocław officeIndustry: Financial ServicesAbout the ProjectOur client operates in the financial services sector and is developing and maintaining a Portfolio Management Tool (PMT) that supports core portfolio management and business operations. As a Senior Python Developer, you will be responsible for designing, developing, and maintaining backend services, business logic, and data-processing solutions that support portfolio modelling, trade workflows, market data ingestion, and operational reporting. The role combines Python backend development, REST API design, database engineering, and ETL pipeline development. You will contribute to the reliability, performance, and maintainability of a business-critical application, working closely with technical and business stakeholders to deliver robust, high-quality solutions. Key ResponsibilitiesDesign, develop, and maintain backend services and REST APIs using Python and Flask. Implement and enhance business logic supporting portfolio management, trade processing, and financial data workflows. Design, develop, and optimize PostgreSQL queries, database operations, and data models. Build and maintain ETL pipelines and batch-processing workflows for market data ingestion, portfolio modelling, and operational reporting. Use Pandas and NumPy to process, transform, and validate structured financial data. Apply clean architecture principles and layered application design, including service, repository, and DAO patterns. Write and maintain unit and integration tests to ensure code quality, reliability, and system stability. Troubleshoot production issues, investigate root causes, and implement long-term solutions. Contribute to code reviews, technical documentation, and continuous improvement of development practices. Work with containerized environments and CI/CD pipelines to support reliable application delivery and deployment. Collaborate with cross-functional teams to translate business requirements into effective technical solutions. Required QualificationsStrong professional experience in Python development, ideally within enterprise environments or business-critical applications. Hands-on experience developing REST APIs using Flask or a comparable Python web framework. Strong SQL skills and practical experience with PostgreSQL, including query optimization, performance tuning, and troubleshooting. Experience designing, implementing, or maintaining ETL pipelines, batch-processing solutions, or workflow orchestration processes. Practical experience with Pandas and NumPy for data manipulation and processing. Good understanding of software architecture and layered application design, including service, repository, and DAO-style patterns. Experience writing and maintaining unit and integration tests for backend applications. Familiarity with Docker or other containerization technologies and CI/CD practices. Strong analytical and problem-solving skills, with the ability to investigate complex technical issues and identify root causes. Ability to work independently, take ownership of technical solutions, and contribute effectively within a collaborative team. Willingness to work in a hybrid model, with 3 days per week in the Wrocław office. Interested? If you are an experienced Python Developer who enjoys building reliable backend systems, optimizing data-intensive applications, and solving complex technical challenges, we would be happy to hear from you.