About WebellianWebellian is a well-established Digital transformation and IT consulting company committed to creating a positive impact for our clients. We are driven by shared values, strong principles, and a passion for innovative and disruptive technologies. We are a community of engineers and senior advisors who work with our clients across industries, playing a deep and meaningful role in accelerating and realizing their vision and strategy.About the positionThe Senior Back-End Developer will design, develop, and maintain scalable back-end systems using Java Spring Boot. The role focuses on building secure REST APIs, implementing data persistence with Hibernate/MySQL, and ensuring robust CI/CD processes. The developer will collaborate with cross-functional teams to deliver high-quality software that meets performance, security, and reliability standards.Key responsibilities Design, develop, and maintain back-end applications using Java Spring Boot and Spring MVC. Implement and maintain RESTful APIs and ensure secure and efficient data exchange. Develop and optimize data persistence layers using Hibernate and MySQL. Ensure application security, reliability, and performance best practices are followed. Collaborate with front-end developers, DevOps, and QA teams to deliver end-to-end solutions. Participate in CI/CD processes to automate build, test, and deployment workflows. Troubleshoot and resolve back-end issues, performance bottlenecks, and security vulnerabilities. Maintain technical documentation and contribute to knowledge sharing across the team. Competencies 3-6 years of experience in back-end development using Java, Spring Boot, and Spring MVC. Strong experience with Hibernate and relational databases, preferably MySQL. Proven experience designing and implementing secure REST APIs. Solid understanding of CI/CD pipelines and automation tools. Knowledge of application security best practices. Strong problem-solving, analytical, and debugging skills. Ability to collaborate effectively across cross-functional teams. Excellent organizational skills and attention to detail. Fluency in English. What we offer Contract under Polish law: B2B or Umowa o Pracę Benefits such as private medical care, group insurance, Multisport card English classes are available Hybrid work (3 days/week on-site) in Warsaw (Mokotów) Opportunity to work with excellent professionals High standards of work and focus on the quality of code New technologies in use Continuously learning and growth International team Pinball, PlayStation & much more (on-site 🤫)