Backend Developer (Java)

Are you a seasoned Java Back-End Developer who enjoys solving complex challenges and designing high-quality, scalable systems? Would you like to work on impactful enterprise projects in one of Poland’s largest financial institutions? Join us and contribute to modernizing critical systems while shaping technical excellence from the inside out.   If you’re driven by clean architecture, automation, and the satisfaction of seeing your code improve performance and reliability - apply today! Key responsibilities • Design and align technical solutions ensuring system integrity, data security, and architectural consistency. • Implement new functionalities according to agreed standards and best practices. • Review code to ensure compliance with standards and design assumptions. • Actively prevent technical debt through refactoring and proactive improvement initiatives. • Support implementation with hands-on coding and technical expertise. • Diagnose and resolve system errors, enhance performance, and estimate the effort for planned changes. Ideal candidate profile • Higher education in computer science or a related field. • Minimum 5 years of experience as a Java Developer in commercial projects. • Solid knowledge of Java 18+, Spring Boot 3+, JPA, and experience with databases (Oracle, PostgreSQL). • Strong experience with Git, Maven/Gradle, CI/CD tools (Jenkins, Ansible), and containerization (Docker, Kubernetes). • Familiar with Linux/Windows environments, REST/SOAP, and Kafka integration. • Understanding of design and architectural patterns and Agile methodologies (ideally Scrum). • Good English (technical reading and communication). • Self-organized, adaptable, and proactive in improving quality and performance.   Nice to have:Experience with Camunda (BPMN), Magnolia DX Core (CMS), Angular/TypeScript/Node.js, cloud (Azure or GCP), Helm, and HTTP servers (Nginx, Apache).Conditions Location: Warsaw Work Model: HybridEmployment Type: B2B contractContract Duration: April-May 2026 (with possible long-term extension)Salary: 140-150 PLN/hRecruitment steps • Initial call with a KUBO recruiter • Technical interview(s) with the client • Final decision and feedback W KUBO naprawdę zależy nam na ludziach. Zapraszamy osoby w różnym wieku, o różnych tożsamościach i sposobach funkcjonowania oraz niezależnie od sytuacji zdrowotnej i rodzinnej. Autentyczność jest dla nas wartością, a naszym celem jest uczciwy i otwarty proces dla wszystkich.   At KUBO, we genuinely care about people. We welcome candidates of all ages, backgrounds, identities, family constellations, health situations, and ways of thinking and interacting with the world. You’re welcome to be yourself - we value authenticity, and we’re committed to creating a fair and inclusive process for everyone.