Fullstack Developer (Java / React)

About the Role We are seeking an experienced Fullstack Developer to join a core engineering initiative for a leading global wealthtech and fund distribution platform. In this role, you will balance backend and frontend development (approx. 50/50 split) using Java and React to build and scale complex applications supporting global investment fund and asset management processes. Key Responsibilities Develop robust backend microservices and application components using Java and Spring / Spring Boot. Build modular, responsive frontend user interfaces using React and JavaScript / TypeScript. Design, build, and integrate high-performance REST APIs. Collaborate with international engineering teams on business and technical requirement analysis. Maintain, refactor, and enhance existing applications within a complex, service-oriented architecture. Troubleshoot, debug, and resolve technical issues across full-stack environments. Candidate Profile Level of Experience: Mid-Senior level with a proven track record as a Fullstack Developer on enterprise-scale systems. Backend Stack: Strong proficiency in Java and the Spring / Spring Boot framework ecosystem. Frontend Stack: Solid hands-on experience building web applications with React, JavaScript, and TypeScript. API & System Design: Good knowledge of REST API development and integration in complex application environments. Languages: Fluent English required for daily communication within an international project setup. Nice to Have Practical experience with microservices architecture and event-driven messaging (e.g., Kafka). Knowledge of containerization and orchestration tools (Docker, Kubernetes). Exposure to CI/CD pipelines and public cloud platforms (AWS, Azure, or GCP). Prior background in financial services, investment banking, or asset management (specifically investment funds / ETFs). Working Model & Logistics Employment Type: B2B Contract Location: Warsaw, Poland (Hybrid model: 2 days per week in-office)