As a **Senior Software Engineer Fullstack** at Mercado Livre, you will design and scale innovative and secure systems that solve real, high-impact problems. You will work in a dynamic environment with cutting-edge technology, applying sound engineering practices, proprietary AI models, and continuous learning, with the purpose of democratizing e-commerce and financial services in Latin America. Imagine\-yourself working on challenging, dynamic, and innovative projects and **being responsible for**: * Participating in all phases of high-impact product development, analyzing requirements and proposing solutions that add value to both technical and business areas. * Collaborating on architecture and scalability decisions for our products. * Ensuring code quality by applying best practices such as code reviews, pair programming, etc. * Building and executing tests for applications. * Monitoring application performance metrics as well as product/business metrics. * Supporting mentorship and development of less experienced developers, actively contributing to their growth. **What we look for in you?** * Experience with Golang or Java for backend development, and Node.js and React.js for frontend development. * Demonstrated knowledge of agile methodologies and processes. * Familiarity with relational and non-relational databases (MySQL desirable). * Proven experience with microservices. * Application of software design principles such as SOLID and Clean Code. * Commitment to continuous improvement and learning new technologies. **Are you excited about making your mark on Latin America's technology landscape?** Apply now and join our mission! Hybrid work model. Location: Florianópolis \- Santa Catarina.