Senior Java Developer (Kafka)

Senior Java Developer (Kafka) 💰 150-200 PLN/h net + VAT 📝 B2B/UoP 📍 Warsaw | Hybrid model: 1 day per week from the office Join an international organization delivering a large-scale Big Data integration platform connecting systems across multiple countries within the logistics industry. This is a strategic migration and modernization initiative focused on building scalable, event-driven solutions that support critical business operations. Your role As a Senior Java Developer, you will be responsible for designing and developing backend services and integrations for a complex enterprise ecosystem. You will help modernize legacy applications, drive technical decisions, and build robust event-streaming solutions used across international markets. What we offer Long-term cooperation on a strategic international program Competitive rate up to 200 PLN/h B2B or employment contract Hybrid work model (1 office day per week) LuxMed and Multisport Opportunity to work with modern technologies including Java, Kafka, Kafka Streams, Kubernetes, and cloud-native architectures Real impact on the development of a global integration platform Technology stack: Java 17+, Spring Boot, Kafka, Kafka Streams, REST API, Microservices, Kubernetes, PostgreSQL/MS SQL/Oracle, Git.
Requirements:
10+ years of experience in software development Strong expertise in Java 17+ and Spring Boot Very strong Kafka knowledge (must-have) Hands-on experience with Kafka Streams Experience building microservices and event-driven architectures Strong understanding of integrations, REST APIs, and messaging systems Experience with relational databases (PostgreSQL, MS SQL, Oracle) Kubernetes and basic DevOps knowledge Fluent English Nice to have: Confluent Kafka experience Confluent Kafka Developer certification
Must have: Java, Spring Boot, Kafka, Kafka Streams, Microservices, REST API, PostgreSQL, MS SQL, Oracle, DevOps, Kubernetes
Nice to have: Confluent Kafka experience, Confluent Kafka Developer Certification
Daily tasks: - Design, develop, and maintain scalable backend services and integrations
– Build event-driven solutions connecting multiple enterprise systems
– Work on large-scale Big Data and data-platform initiatives
– Modernize legacy applications and migrate them to modern architectures
– Define technical solutions and contribute to architectural decisions
– Collaborate with product, business, and engineering teams
– Mentor less experienced developers and promote best practices
– Support production environments and ensure solution reliability