Java/Kotlin Developer SSR/SR

About the Role We are looking for a highly skilled Senior Backend Developer with strong experience in Java and hands-on knowledge of Kotlin for backend development. The ideal candidate will be responsible for designing, developing, and maintaining scalable backend services and RESTful APIs within a microservices-based architecture. This role requires collaboration with cross-functional teams including Product, Frontend, DevOps, and QA, as well as active participation in system design and architectural decisions. Key Responsibilities Design, develop, and maintain backend services and RESTful APIs using Java and Kotlin Build and enhance microservices-based architectures Work with frameworks such as Spring / Spring Boot (Java or Kotlin) Integrate backend services with SQL and/or NoSQL databases Ensure code quality through unit testing, code reviews, and best practices Collaborate with Product, Frontend, DevOps, and QA teams Troubleshoot, debug, and optimize backend applications Participate in system design discussions and architectural decisions Required Qualifications 5+ years of backend development experience using Java Hands-on experience with Kotlin for backend development Strong experience building REST APIs and backend services Experience with Spring Boot and Hibernate/JPA Solid understanding of microservices architecture Experience working with relational databases (PostgreSQL, MySQL, Oracle, etc.) Familiarity with Git, CI/CD pipelines, and build tools (Maven/Gradle) Good understanding of object-oriented design and design patterns Nice to Have (To Be Validated During Interview) Experience with cloud platforms such as AWS, Azure, or GCP Exposure to Docker and Kubernetes Experience with messaging systems such as Kafka or RabbitMQ Knowledge of security protocols such as OAuth2 and JWT Experience migrating services from Java to Kotlin (experience in at least one is acceptable) Location: Martínez, Buenos Aires, Argentina Work Modality: Hybrid (On-site presence required 1–2 times per week)