Senior Java Engineer

April 27, 2026 Auto Import

Ciklum is looking for a Senior Java Engineer to join our team full-time in Poland.We are a custom product engineering company that supports both multinational organizations and scaling startups to solve their most complex business challenges. With a global team of over 4,000 highly skilled developers, consultants, analysts and product owners, we engineer technology that redefines industries and shapes the way people live.About the role:As a Senior Java Engineer, become a part of a cross-functional development team engineering experiences of tomorrow. Seeking a developer to lead the test-driven migration of a legacy Java EE application to a modern Spring Boot architecture, including transformation from MySQL to MongoDB.Responsibilities:<ul><li>Analyze existing Java EE components and document business logic</li><li>Design clean, testable Spring Boot services and data access interfaces</li><li>Plan and execute MySQL to MongoDB data model transformation</li><li>Write unit/integration tests prior to implementation</li><li>Execute incremental migration with parallel validation</li><li>Ensure performance parity with legacy application</li></ul>Requirements:<ul><li>Java/Spring Boot - Strong experience building enterprise applications, REST APIs, and data access layers with Spring Data</li><li>Jakarta EE/Java EE - Ability to analyze and deconstruct legacy Java EE components (EJBs, JPA, CDI)</li><li>MySQL - Deep understanding of relational data models and query optimization</li><li>MongoDB - Experience with NoSQL patterns, document modeling, and Spring Data, MongoDB</li><li>TDD/Unit Testing - Proven track record writing comprehensive test suites before implementation (JUnit, Mockito, Testcontainers)</li><li>Python - For scripting, automation, and migration tooling</li><li>LLM/AI Tools - Experience leveraging AI for code analysis, conversion assistance, and documentation generation</li><li>Kafka - Understanding of event-driven architectures for data synchronization</li><li>Docker/Kubernetes - Familiarity with containerized deployments</li></ul>What`s in it for you?<ul><li>Strong community: Work alongside top professionals in a friendly, open-door environment</li><li>Growth focus: Take on large-scale projects with a global impact and expand your expertise</li><li>Tailored learning: Boost your skills with internal events (meetups, conferences, workshops), Udemy access, language courses, and company-paid certifications</li><li>Endless opportunities: Explore diverse domains through internal mobility, finding the best fit to gain hands-on experience with cutting-edge technologies</li><li>Flexibility: Enjoy flexibility – full remote working possibilities</li><li>Care: We’ve got you covered with company-paid medical insurance, mental health support, and financial & legal consultations</li></ul>About us:At Ciklum, we are always exploring innovations, empowering each other to achieve more, and engineering solutions that matter. With us, you’ll work with cutting-edge technologies, contribute to impactful projects, and be part of a One Team culture that values collaboration and progress. With delivery centers in Wrocław and Gdańsk, our 300+ professionals in Poland drive forward-thinking solutions for global clients. Join a community where collaboration sparks innovation—and your impact reaches millions.Want to learn more about us? Follow us on <a href="https://www.instagram.com/ciklum/" style="text-decoration: none;">Instagram</a>, <a href="https://www.facebook.com/CiklumPoland" style="text-decoration: none;">Facebook</a>, <a href="https://www.linkedin.com/company/ciklum/" style="text-decoration: none;">LinkedIn</a>.Explore, empower, engineer with Ciklum!Interested already? We would love to get to know you! Submit your application. We can’t wait to see you at Ciklum.

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