Sr Java Developer (paytech)

About the Project    Our client is a paytech company expanding in Europe.  You will work in a truly international environment with colleagues across all Nexi group locations. The platform is built on a modern microservices architecture, offering plenty of opportunities to tackle complex challenges and make a significant impact. First customers have already been migrated, but there is still a big backlog of new features that need to be implemented.   Work Mode: one day per week at the office is required (Warsaw)   Technology stack in use:• Java 21 (Spring Boot 3)• OpenShift / Kubernetes• Apache Kafka / Rabbit MQ for streaming and queuing• MongoDB• Oracle Database• Multiple DevOps tools for development, automation and monitoring Job Responsibilities • Design, develop and support testing payment services features together with the team • Resolve issues by troubleshooting and root cause analysis and support in production issueanalysis when needed • Ensure high quality via unit testing and code reviews • Demo and document the results of work in demo sessions Expectations •  8+ years of experience with Java development • Understanding of microservices architecture and distributed systems • Familiarity with API design principles • Daily use of MongoDB, Kafka, Docker, Kubernetes • Familiarity with agile environment  • Fluency in English • Nice to have: experience in designing and implementing high-throughput, low-latency systems capable of handling large data volumes; Groovy, Maven, Jenkins; Knowledge of the Card Processing domain;  We offer • Ongoing support from a dedicated agent who is caring about your project continuity, contact with clients, necessary formalities, work comfort, and development.  • Career Development Program – advice on career planning based on the latest trends and market needs in IT, including consultations with career agents and mentors.  • Access to 7N Learning & Development – a development and educational platform offering webinars, a library of articles and industry reports, and frequent invitations to both one-time and recurring events focused on technical, business, and lifestyle topics.  • Spectacular events, both for you (e.g., annual Kick-Off trip, Christmas parties, or Summer Olympics sports events) and for your loved ones (e.g. family picnics),  • Professional growth Professional growth beyond your current project. You can actively engage in knowledge sharing through the 7N Services offering, designed for 7N clients.  • Connections and access to the expertise of top IT professionals in the market – the average professional tenure of our consultants in Poland is over 10 years,  • A complete benefits package, including funding for medical care, life insurance, sports cards for you and your loved ones, as well as discounts in stores in Poland and abroad.    About 7N Constantly searching for projects, difficult rate negotiations, lack of development support – sounds familiar? At 7N, you gain not only stability of contracts but also the personal involvement of a dedicated agent who ensures your professional comfort and continuous access to development initiatives.  Our mission is to provide stable and rewarding collaborations that drive your success as an IT expert and the success of our clients. We build long-lasting relationships based on Scandinavian values and 30 years of experience creating IT solutions for over 200 organizations.