Java Developer (Payment)

Role- Senior Java Backend Developer- Payments AI Enabled Spec Driven Development Location Gdynia and Warsaw Poland- Extensive years in Java backend development including hands on years in payments or banking Role Summary We are looking for a senior Java backend developer with hands on payments experience to design and build secure high performance payment services The candidate should be expert in Core Java Spring Boot microservices and Kafka They should also use AIassisted engineering especially spec driven development to deliver high-quality software faster Working directly with Nordic client stakeholders they will own solutions from specification through to production Key Responsibilities Design develop and maintain scalable payment microservices for payment initiation clearing settlement and reconciliationBuild eventdriven high throughput flows using Kafka with idempotency exactly once handling and reliable retry and error handlingWrite clear specifications requirements acceptance criteria API contracts data models and use them as the single source of truth for AIassisted design code generation and testingUse AI coding assistants and agents eg GitHub Copilot Spec Kit or similar to turn specifications into plans tasks code and tests Critically review all AIgenerated output for correctness security and complianceDesign REST APIs contract first using OpenAPI and keep specifications and code in syncMake sure solutions meet banking grade standards for security resilience audit and data protectionWork with product owners architects and testers in Agile SAFe teams Mentor other developers on modern Java and AIassisted engineering practicesSupport production and analyse incidents for business critical payment systemsRequired Skills Java and backend Expert in Java 17 Java 21 preferred Spring Boot 3 Spring Framework Spring Data Hibernate JPASpring Security with OAuth2OIDC JWT and mTLSMicroservices patterns API gateway circuit breaker saga outbox CQRS and event sourcingKafka producers consumers partitioning schema registry Kafka StreamsContractfirst REST API development OpenAPISwagger API versioning and documentationPayments domain Handson experience with ISO 20022 messages pain pacs camt and SWIFT MTMX migrationKnowledge of SEPA Credit Transfer SEPA Instant SCT Inst SEPA Direct Debit and realtime payment schemes such as TIPSRT1Understanding of the payment lifecycle initiation validation screening routing clearing settlement and reconciliationAwareness of EU regulation including PSD2Open Banking APIs the EU Instant Payments Regulation DORA GDPR and AMLsanctions screeningAI and specdriven development Practical experience with specdriven development writing structured testable specifications that drive AIgenerated design code and testsSkilled use of AI coding assistants and agents in daily development prompt and context engineering iterating on output generating testsAbility to validate AIgenerated code for quality security and performance and to apply guardrails such as code review static analysis and policy checksUnderstanding of responsible AI in regulated environments no sensitive data in prompts traceability human oversightData and databases Strong relational database skills Oracle MS SQL PostgreSQL complex queries performance tuning transactions and lockingDatabase migration tools Flyway LiquibaseDevOps and qualityDocker and Kubernetes OpenShift a plusCICD Git Maven BambooJenkinsGitHub Actions Ansible artifact repositories Nexus ArtifactoryTesting JUnit 5 Mockito Testcontainers contract testing Pact Spring Cloud Contract performance testingCode quality and security SonarQube static and dependency security scanning SASTSCA OWASP Top 10Shell scripting and scheduling tools UC4Automic AutoSys ControlMWays of working Experience in Agile and SAFe deliveryGood to Have Cloud platforms Azure AWS GCPObservability Grafana Prometheus OpenTelemetry AppDynamics ELKSplunkExperience with Nordic banks or payment providersOlder stacks for maintenance work WebLogic Tomcat JSP JavaScript BootstrapCertifications Oracle Java Spring Professional Kubernetes CKAD cloud certificationsSkills Mandatory Skills : AI/Generative AI, Java, Java Microservices, Java SpringBoot, Kubernetes Good to Have Skills : Agile (Value-Driven Delivery), Docker, Java SpringCloud, JavaScript, Payments (SWIFT, ISO20022, Real-Time, Instant, Request to Pay, Domestic, Cross-Border, High Value, Low Value and Mass Payments)