Job Description

We are looking for Senior Java Developers to join a long-term payments technology programme focused on terminal management systems supporting more than 300,000 payment terminals across multiple hardware vendors. The role combines backend development, integrations, and system modernisation within a complex enterprise payments environment.

This is a hands-on Java role working across both legacy and modern architectures, including migration from WildFly-based systems to Spring Boot microservices, with strong focus on integrations, distributed systems, and payment infrastructure reliability.

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 / WildFly
• Knowledge of scanning tools such as Fortify or Sonatype
• English B2
• Full availability in the Polish time zone
• Ability to work 4 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
Flexible hybrid model (4 days/ week on-site in Warsaw)

About Madiff

We are an international Innovation, IT and high-tech engineering consulting company that delivers unique value in a wide variety of industries.

Our mission is to add value to our customers businesses by providing digital and technological innovation services, delivering disruptive results and making our clients stand out in their market.

We are driven by a creative and innovative consulting approach strongly oriented to getting results. We MAKE THE DIFFERENCE.

Warsaw

Prosta 20

Wrocław

Rybacka 7

Lublin

Grottgera 2

Industry

IT & Software

Company Size

51-200 employees

Headquarters

Warszawa, PL

Year Founded

2015

Website

madiff.eu

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