Senior Java Full-Stack Developer with React w Kraków, Polska

We are looking for a Senior Java Full-Stack Developer with strong React expertise to join our team.

In this role, you will lead the design and delivery of complex, highly scalable web applications across both front-end and back-end layers. You will drive technical decisions, mentor fellow engineers, and partner closely with cross-functional teams to shape high-quality solutions that address strategic business and user needs.

This role offers a hybrid model, with 3 days per week working from our office in Kraków.

Architect, build, and maintain enterprise-grade web applications using React and Java Design, develop, and evolve REST APIs, ensuring scalability, security, and maintainability Define and optimize database solutions using PostgreSQL, including advanced query tuning and data modeling Establish and promote best practices for writing clean, maintainable, and well-tested code Lead code reviews, troubleshoot complex issues, and guide testing and debugging strategies Collaborate with product, QA, and engineering teams to define technical direction and deliver impactful features Mentor mid-level and junior developers, fostering technical growth within the team Contribute to architectural discussions and influence long-term technology choices 3+ years of experience in full-stack development Strong proficiency in React and modern JavaScript/TypeScript, including state management and performance optimization Solid background in Java backend development, with deep expertise in Spring and Spring Boot Proven experience designing, building, and scaling RESTful APIs Advanced knowledge of PostgreSQL, including schema design, complex queries, indexing, and performance tuning Hands-on experience with Git, CI/CD pipelines, and agile methodologies Demonstrated ability to lead technical initiatives and mentor other engineers English proficiency at an Upper-Intermediate level (B2) or higher Solid experience with Docker and CI/CD automation Hands-on experience with cloud platforms (Azure preferred) Exposure to microservices architecture and distributed systems Experience with system design and architectural decision-making at scale