Senior Java Developer – TMS

Build the backbone of next-gen payments—design, harden, and scale the Terminal Management System.

Location & work model Warsaw-based opportunity with on-site work model (4 days office + 1 day WFH per week).

As a Senior Java Developer, you will be working for our client on TMS (Terminal Management System)—a complex platform managing 300,000+ payment terminals. The system delivers a uniform approach to operating terminals from different hardware vendors and consists of two major components: TMS (WildFly-based) and RTMS (Spring Boot-based). You will help advance a solution that integrates with many internal and external systems and is subject to regular security scanning.

Your main responsibilities:

• Design and implement IT solutions based on analytical and technical documentation.

• Review analytical documentation and translate requirements into technical direction.

• Create and maintain technical documentation to support development and quality assurance.

• Perform technical upgrades of existing systems, improving stability and maintainability.

• Work with legacy code, conducting enhancements while preserving functional correctness.

• Conduct reverse engineering using existing source code, documented business processes, and UI/database access.

• Define and build test cases for automated testing to ensure reliable releases.

You're ideal for this role if you have:

• At least 5 years of professional experience in Java development.

• Strong knowledge of Java 8+ and object-oriented programming.

• Experience with independent design, implementation, documentation, and testing of application components.

• Practical knowledge of Spring / Spring Boot, Hibernate/JPA, and JEE frameworks.

• Practical knowledge of message queue systems, particularly RabbitMQ.

• Practical experience with Maven, Git, GitLab, GitLab CI/CD, Jenkins, Nexus, and Jira.

• Knowledge of relational databases, in particular Oracle.

• Practical experience with RESTful API design and system integration.

It is a strong plus if you have: (optional)

• Experience with distributed systems.

• Experience with application servers, especially JBoss/WildFly.

• Knowledge of scanning tools such as Fortify and/or Sonatype.

Language Required for the role :

• Polish (required for the role) — communicative level.

• English — B2 level.

Eligibility for the role :

• Only candidates with an existing legal right to work in Europe will be considered for this role.

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• Interested? Apply now and include your CV (preferably in English) along with a statement confirming your consent to the processing and storage of your personal data.