Senior Java Developer

We are seeking a Senior Java Developer to contribute expertise in backend engineering for one of the leading global payments technology environments. This long-term opportunity offers a hybrid work model with 1 day per week onsite presence in either the Warsaw or Gdańsk office (approximately 4 days per month), providing the chance to help shape and elevate backend systems, microservices, and APIs that power high-impact financial solutions in the payments landscape - a sector central to today’s digital commerce and real-time transaction processing. 🔧 What You’ll Do • Design and implement backend systems using Java and modern frameworks • Develop microservices and REST/SOAP-based APIs • Take part in architecture reviews focused on optimization and scalability • Debug, profile, and optimize applications • Write clean, maintainable technical documentation • Work with distributed systems and containerized environments 🛠 Required Skills & Experience • 7+ years of experience in Java development • Expertise in Java 8+ platform • Solid experience with Spring / Spring Boot, Spring MVC, JPA/Hibernate • Strong background in microservices, including Kafka or equivalent messaging systems • Deep understanding of SOA principles and web services (REST & SOAP) • Experience with relational and NoSQL databases • Exposure to containerization technologies (Docker) and orchestration • Familiarity with Git (version control), Maven, Jenkins, or similar build/CI tools • Experience with frontend technologies (React or advanced JavaScript) is a plus 🧠 Nice to Have • Prior experience with cloud platforms (e.g., Azure, AWS) • Knowledge of automated testing and deployment practices 📍 Work Model • Hybrid: 1 day per week from the Warsaw or Gdańsk office (4 days per month)