Python Developer
Summary
Python developer (junior or senior) building and optimizing data pipelines and processing services for high-scale transaction fee calculation and portfolio management engines serving €1T+ asset platforms. Core stack is Python, SQL, and relational databases (PostgreSQL, Polars valued); hybrid role in Warsaw on a B2B contract.
Location: Warsaw, Poland (Hybrid, weekly office visits)
Contract Type: B2B Contract
Start Date: ASAP
About the Project
We are expanding our data engineering team to build and maintain high-scale transaction fee calculation and portfolio management engines supporting platforms managing over one trillion euros in assets. You will design, develop, and optimize data processing workflows handling large-scale datasets, ensuring peak operational performance, database resilience, and processing speed.
Key Responsibilities
- Build and maintain robust data pipelines and automated processing services using Python and relational database engines
- For Senior engineers: lead advanced SQL query optimization, indexing strategies, execution plan tuning, and performance profiling across tables containing millions of rows
- Integrate data frameworks to streamline ingestion, transformations, and transaction fee logic
- Collaborate closely with distributed engineering and infrastructure teams across Europe in a hybrid structure
Requirements
- Junior Level: 1 to 2 years of commercial software or data engineering experience with strong Python and SQL skills
- Senior Level: 3 to 5 years of commercial experience with expert-level SQL and deep knowledge of performance tuning at enterprise scale
- Bachelor of Science (BSc / Inżynier) degree in Computer Science, Software Engineering, or a related technical discipline
- Hands‑on experience with relational databases, with PostgreSQL strongly preferred
- Familiarity with high‑throughput Python data libraries; experience with Polars is a distinct advantage
- Strong communication skills in English (B1/B2 minimum for Junior, fluent for Senior)