Senior Java Engineer

Senior Software Engineer — Java / Microservices  Start date: ASAP | Contract type: B2B  (145-170pln) | Work mode: 100% Remote   About the Team You'll be joining a multidisciplinary team of senior engineers within a Consumer & Merchant domain, working on end-to-end parcel creation flows and some of the company's largest technical initiatives. The team operates with high autonomy — engineers have real influence over architectural decisions and drive solutions from analysis all the way to production. The culture is built on knowledge sharing, mutual respect, and engineering excellence, with a genuinely friendly atmosphere. Your Responsibilities • Design and implement microservices following Hexagonal Architecture principles within a large-scale distributed system • Drive topic analysis and requirement discovery — from business needs to solution architecture and delivery • Build and maintain event-driven integrations using Kafka, Avro, and the Transactional Outbox pattern • Write comprehensive automated tests: unit, integration, contract (Spock, Testcontainers, Spring Cloud Contract) • Participate actively in code reviews and help raise the bar on code quality • Work in a CI/CD environment: GitLab CI, Docker, Kubernetes + Helm (GitOps) • Use AI-assisted development tools (Claude Code is the team standard) as a primary daily productivity tool — agentic, AI-first development is how this team operates Tech Stack Language & Frameworks: Java 21, Spring Boot 3.x/4.x (MVC & WebFlux), Gradle Databases: PostgreSQL (JPA/Hibernate, R2DBC), MongoDB Messaging: Apache Kafka + Avro + Confluent Schema Registry Patterns: Hexagonal Architecture, Microservices, Event-Driven Design, Transactional Outbox Security: OAuth2 / JWT, Spring Security, OpenFGA Testing: Spock Framework, Testcontainers, WireMock, REST-Assured, ArchUnit, PIT Mutation Testing Infrastructure: GitLab CI, Docker, Kubernetes + Helm (GitOps) Observability: Micrometer, Prometheus, SonarQube, Checkstyle AI Tooling: Claude Code (mandatory) / GitHub Copilot / Cursor Requirements Must have: • Strong, hands-on experience with Java 21+ and Spring Boot MVC • Solid knowledge of Kafka, PostgreSQL and/or MongoDB • Familiarity with Hexagonal / Clean Architectureerns:** Hexagonal Architecture, Microservices, Event-Driven Design, Transactional Outbox Security: OAuth2 / JWT, Spring Security, OpenFGA Testing: Spock Framework, Testcontainers, WireMock, REST-Assured, ArchUnit, PIT Mutation Testing Infrastrucy proficiency with AI coding tools — Claude Code** is the team standard; experience with agentic development workflows is a strong plus Nice to have: • Experience with Spring WebFlux (reactive stack) • Familiarity with OpenFGA or similar fine-grained authorisation systems • Background in Consumer-Driven Contract testing (Spring Cloud Contract) What Makes This Role Challenging • • Complex distributed system — dozens of microservices with numerous communication channels; understanding the big picture is as important as writing good code • Near-100% uptime requirement — business-critical systems where reliability and fault tolerance are non-negotiable • High autonomy from day one — independently analyse topics, identify stakeholders, and deliver solutions end-to-end • AI-first way of working — using Claude Code and agentic workflows to accelerate delivery is a core part of how the team operates, not a nice-to-have   Why apply for an Antal job offer? When your application is successful, you will be supported by a dedicated Consultant who will stay in regular contact with you (via email or phone), help you prepare for interviews with your future employer, and ensure a smooth and professional recruitment process. About Antal Antal is a leading recruitment and HR advisory company, present in Poland since 1996 and later expanded to the Czech Republic and Hungary. Across the CEE region, we employ around 150 professionals who deliver a full range of services – from specialist and executive recruitment, employee outsourcing and HR consulting, to employer branding and market research. Our division-based structure combines deep industry expertise with functional specialisation, enabling us to provide tailored solutions for companies in every sector. We act as a trusted partner for both employers and candidates, sharing our knowledge and guiding them through every stage of the talent journey. We connect exceptional people with the right opportunities and help organisations build successful teams. Discover our latest job openings: https://en.antal.pl/candidates Follow us on LinkedIn: https://www.linkedin.com/company/antalpoland