Senior Python Engineer

For our client, a leading, high-growth global fintech company – we are looking for an experienced Senior Python Engineer to join a key engineering team responsible for the company’s core data foundation. The project focuses on building, optimizing, and scaling a cloud-native, high-throughput Data Platform designed to ingest, process, and distribute massive datasets in real-time. This platform serves as the backbone for various downstream analytical systems, requiring extreme reliability, performance, and scalability. This is a fantastic opportunity for a strong Python generalist who enjoys solving complex distributed system problems, optimizing data flows, and working with modern cloud architectures. Responsibilities Backend & Pipeline Development: Design and develop scalable backend services and high-performance data processing pipelines using Python. Performance Tuning: Identify bottlenecks and optimize system performance, focus on concurrency, throughput, and low-latency execution. Data Integration & Storage: Build robust integrations with modern cloud-native storage solutions and databases to manage large-scale datasets efficiently. Collaborative Engineering: Work closely with cross-functional technical teams to understand data requirements and deliver reliable API services and platform features. Engineering Excellence: Maintain top-tier coding standards, emphasizing clean code, robust testing (unit/integration), automation, and security. Requirements 8+ years of professional backend software development experience (with a strong track record in building scalable, production-grade systems). Deep expertise in Python (advanced OOP, concurrency/multiprocessing, memory management, data structures, and algorithms). Solid experience with data-centric libraries such as Pandas, NumPy, or similar data processing frameworks. Experience with large-scale data storage formats (e.g., Parquet, JSON, or column-oriented databases) and relational/NoSQL databases. AI-assisted development mindset: Comfortable utilizing AI tools to accelerate delivery, while maintaining strong developer judgment regarding validation, testing, security, and refactoring. What our client offers: Hybrid work model in Warsaw (minimum 3 days a week in the office - strictly non-negotiable). Contract of Employment (UoP) with increased tax-deductible costs (KUP). Private medical care (including full dental care). Lunch card to cover your daily meals. Multisport card.