Summary: We are seeking a highly skilled Senior Backend Developer with strong Java and Kotlin experience to design, develop, and maintain scalable backend services and RESTful APIs within a microservices architecture. Highlights: 1. Design and develop backend services and RESTful APIs using Java and Kotlin 2. Build and enhance microservices-based architectures with Spring / Spring Boot 3. Collaborate with cross-functional teams on system design and architecture Descripción del empleo: 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)