At **LeaderMedia**, we help companies scale their technology by developing proprietary projects or providing qualified intellectual capital to strengthen internal teams. We are looking for a person passionate about technology, performance, and user experience to join our team. **Key Responsibilities:** * Design and develop robust, well-documented RESTful (and/or GraphQL) APIs. * Write automated tests (unit, integration, and end-to-end) to ensure code reliability. * Model databases and optimize queries for high performance. * Implement complex business logic and integrations with external systems. * Monitor applications and address bugs and performance bottlenecks. * Collaborate in defining architecture (Microservices or Modular Monolith). **Mandatory Requirements (Hard Skills):** * Solid experience with Node.js and Bun. * Experience with Express.js, Fastify.js, and Nest.js. * Proficiency in Relational Databases (e.g., PostgreSQL, MySQL) and/or NoSQL (e.g., MongoDB). * Practical experience with automated testing. * Knowledge of architectural principles (SOLID, Clean Architecture, DDD). * Experience with Docker and version control (Git). * Experience with messaging systems (RabbitMQ, Kafka) and caching (Redis). **Nice-to-Have:** * Knowledge of Cloud platforms (AWS, Azure, or Google Cloud). * Familiarity with other programming languages (e.g., PHP, Rust, Go, and/or Python). * Experience with CI/CD pipelines. Job Type: Freelance / PJ Compensation: R$5\.000,00 \- R$10\.000,00 per month Experience: * Years of Backend experience (Required) Work Location: Remote