NOTE: This is a contracting position working for a US Client. You must be located in South America and be fluent in English. Your resume must be submitted in English. The Client is looking for a Full Stack Senior Software Engineer with proven expertise in software development activities including requirement analysis, design, implementation, and testing. The position will be responsible for the end-to-end lifecycle of changes: from analysis to the usage of the features on production. This is a FULL TIME REMOTE position, that will require leading/mentoring junior team members and working with geographically distributed teams in multiple time-zones. Key Responsibilities: Backend Development: Design, implement, and maintain high-performance RESTful APIs using Java (preferably Spring Boot) for our web applications. Frontend Development: Build and maintain responsive and dynamic user interfaces using React and TypeScript, ensuring a seamless user experience. System Architecture: Contribute to the architecture and design of our application stack, ensuring scalability, reliability, and security. Collaboration: Work closely with cross-functional teams, including product management, UX/UI design, and DevOps, to deliver features that align with business goals. Code Quality: Write clean, maintainable, and testable code. Participate in code reviews, provide mentorship to junior developers, and advocate for best practices in both backend and frontend development. Testing & Debugging: Ensure the quality and performance of the application through unit testing, integration testing, and debugging. Performance Optimization: Identify and resolve performance bottlenecks on both the client and server sides. Agile Development: Actively participate in Agile ceremonies (daily stand-ups, sprint planning, retrospectives) and contribute to continuous improvement of the development process. Required Skills and Expertise: Backend Expertise: NOTE: These skills are REQUIRED. Anything less than the listed number of years will be rejected. 7 years of experience developing server-side applications with Java. 3 years of experience in Java frameworks such as Spring Boot or similar. 3 years of experience with RESTful APIs, microservices, and event-driven architectures. 3 years of experience with databases (MySQL/NoSQL) and experience with database design and optimization. Frontend Expertise: NOTE: These skills are REQUIRED. Anything less than the listed number of years will be rejected. 3 years of experience developing web applications using React. 3 years of experience using TypeScript. Experience with state management libraries (e.g., Redux, Context API). General Skills: Strong understanding of software engineering principles, design patterns, and best practices. Experience with version control (Git) and CI/CD pipelines. Strong problem-solving skills and attention to detail. 2 years experience leading/mentoring other software engineers Excellent communication and teamwork skills. Nice to Have: Experience with cloud platforms (AWS, Azure, GCP). Familiarity with Docker and Kubernetes. Familiarity with automated testing frameworks (e.g., Jest, JUnit). Knowledge of DevOps practices and tools. SALARY: will be based on experience but is paid in USD per hour worked. Timesheets are submitted monthly and paid within 2 weeks. NOTE: candidate must have own company, willing to create one or use an intermediary like Braintrust to establish the Client - Contractor relationship