Senior Java Developer

We are looking for Senior Java Developers to join a long-term payments technology programme supporting a large-scale terminal management platform. The role focuses on backend development, enterprise integrations, system modernisation, and the gradual transformation of a business-critical platform managing hundreds of thousands of payment terminals.

This is a hands-on engineering position requiring strong Java expertise, experience with distributed systems, and the ability to work independently within a complex enterprise environment that combines modern technologies with legacy components.

Responsibilities

• Design and implement IT solutions based on analytical and technical documentation
• Review analytical documentation and translate it into technical implementation
• Create and maintain technical documentation
• Support technical upgrade and modernisation of the existing system
• Work with legacy code and contribute to gradual system migration
• Conduct regular application scans and remove vulnerabilities
• Build and maintain integrations with internal and external systems
• Work with distributed transactions, queues, caching, and database integrations Requirements
• Very good knowledge of Java 8+ and object oriented programming
• Practical experience with Spring, Spring Boot, Hibernate/JPA, and JEE
• Experience designing, implementing, documenting, and testing application components independently
• Practical knowledge of RabbitMQ or other message queue systems
• Good knowledge of Maven, Git, GitLab, GitLab CI/CD, Jenkins, Nexus, Jira
• Knowledge of relational databases, especially Oracle
• Practical experience with REST API design
• Experience with system integrations and distributed systems
• Experience with application servers such as JBoss / Wild. Fly
• Knowledge of scanning tools such as Fortify or Sonatype
• English B2
• Fluent Polish
• Full availability in the Polish time zone
• Ability to work 5 days per week from the Warsaw office Nice to have
• Experience in payments, acquiring, terminal management, or financial services
• Experience with SOAP, RMI, database links, or direct database integrations
• Experience with Hazelcast or distributed caching
• Experience with distributed transaction patterns such as two phase commit or Saga
• Experience working with legacy systems and migration programmes
• Experience with GWT / GWTExt Benefits
• Solid, competitive salary
• Work in a multinational environment on international projects
• Comprehensive healthcare
• Long-term B2B contract with a stable project pipeline