Senior Java Developer

OverviewLocation:Dublin or Manchester (Hybrid)Reports to:Engineering ManagerAbout the RoleWe are seeking a highly skilled Senior Java Developer to lead the modernization of our legacy monolithic architecture by decomposing SOAP-based services into stateless RESTful microservices.You will be responsible for transitioning our legacy SOAP-based services to RESTful, scalable microservices using Spring Boot, deployed in AWS via Docker and Kubernetes (or ECS).This is a high-impact role where your expertise will directly influence system scalability, performance, and developer experience.Key ResponsibilitiesApply domain-driven design and stateless principles to migrate business functionality from the monolith to a modern architectureLead the decomposition of tightly coupled SOAP services into independently deployable microservicesDesign and implement scalable, stateless REST APIs using Spring Boot and SwaggerHubLead the transformation from SOAP/XML to REST/JSON for internal and external APIsServe as the front controller for managing requests and orchestrating backend service flowsDevelop and deploy containerized microservices using Docker and Kubernetes, or AWS ECSImplement cloud-native architecture patterns for high availability, fault tolerance, and scalability in AWSIntegrate with API Gateway, Lambda, and CloudFormation or other IaC tools for provisioning infrastructureTesting & QualityWrite comprehensive integration, unit, and API tests using JUnit, Mockito, Postman, etc.Debug REST-to-SOAP interactions to ensure seamless migration and data integrityChampion CI/CD and test automation practices across the teamPerformance, Caching & DevOpsOptimize performance with caching solutions (e.g., Redis, Memcached)Maintain stateless service architecture principlesContribute to observability with Prometheus, Grafana, and ELK StackCollaborate closely with product, QA, DevOps, and platform teamsMentor junior engineers and support technical decision-making across sprintsAdvocate for engineering excellence, TDD, and best practices in software deliveryRequired Skills & ExperienceExperience leading end-to-end migration projects from SOAP-based systems to scalable, domain-aligned microservicesProven experience decomposing monolithic applications and rebuilding them as RESTful microservices7+ years in Java development with strong expertise in Spring BootStrong knowledge of REST architecture principles and best practicesProven experience designing and building REST APIs at scaleDeep understanding of SOAP-to-REST transformationsHands-on with Docker and either Kubernetes or AWS ECS (Elastic Container Service)Proficiency in one or more Infrastructure as Code (IaC) frameworks: Terraform, AWS CloudFormation, or AWS CDKProficient with CI/CD tools (e.g., Jenkins, GitLab CI, AWS CodePipeline)Strong testing discipline with tools like JUnit, Mockito, Postman, or KarateExperience with OAuth2, JWT, OpenID ConnectFamiliarity with Java 8+ and awareness of Java ***** improvementsPreferred SkillsExperience with API Gateways (AWS API Gateway, Kong)Knowledge of Kafka, RabbitMQExperience with serverless architectures (e.g., AWS Lambda)Broader experience with Infrastructure as Code tooling and best practicesAbout DatalexDatalex's purpose is to transform airline retail.Datalex is a market leader in airline retail technology, offering unique products that enable airlines to drive revenue and profit as digital retailers.Datalex has a strong track record of delivering digital retail transformation for progressive airline brands worldwide, including Aer Lingus, easyJet, JetBlue Airways, Air China, Edelweiss, Air Transat, and Air Macau.The Group is headquartered in Dublin, Ireland, and maintains offices across Europe, the USA and China.In ****, Datalex was awarded the 'Great Place to Work' and 'Best Workplaces in Tech' certifications.Datalex plc is a publicly listed company on Euronext Growth, Dublin.Learn more at or follow on LinkedIn @Datalex.Do you have eligibility to work and reside in the country of employment?*Are you currently based in the country of employment?How many years experience do you have?*We currently operate in a hybrid model.Would you be willing to be onsite 2 days per week?*Yes No#J-*****-Ljbffr