Full Stack Engineer

**QAT Global – 100% Remote (Brazil Only – CLT hire)** QAT Global, a US\-based IT consulting firm with over 30 years of experience, is seeking highly\-skilled **Java Full\-Stack Developers** with strong English communication skills to join our global engineering team. You will collaborate directly with our US\-based customer and work with distributed development teams across the US, Costa Rica, and Brazil. **About the Role** As a Java Full\-Stack Developer, you will be responsible for building mission\-critical backend services and front\-end components that support a large\-scale financial platform. You will work across domains involving profiles, billing, ledger, invoicing, and payment flows, contributing to both core business logic and customer\-facing UI experiences. This role requires strong expertise in modern full\-stack engineering combined with practical experience using **AI\-assisted development workflows** , LLMs, and prompt engineering to accelerate delivery while maintaining high quality. **Responsibilities** * Develop and maintain backend services across key financial modules (Profile, Billing, Ledger, Invoice, Recurring, Receipt, Remittance). * Build and enhance front\-end components used in the Administration UI and Payment Widget. * Implement business logic, domain models, API endpoints, and cross\-service integrations. * Work with frameworks defined by the architecture team (likely Java/Kotlin on the backend, TypeScript/React on the frontend). * Collaborate closely with QA engineers to ensure functional completeness and application stability. * Use **AI\-assisted workflows** to generate code, improve documentation, and create automated tests. * Participate in agile ceremonies and work effectively with distributed teams. **Required Experience** * Strong hands\-on experience with **Java (Spring Boot)** , **Node.js** , and **React** . * Experience with **PostgreSQL** and relational data modeling. * Familiarity with **Security / DevOps / Cloud** practices. * Knowledge of **GitHub CI/CD pipelines** , versioning, and workflow automation. * Practical usage of **GitHub Advanced Security** (CodeQL, secret scanning, dependency checks). * Experience with **AWS IAM** (roles, policies, permission boundaries). * Experience deploying or maintaining workloads on **EC2** , **RDS** , and **SQS** . * Working knowledge of LLM capabilities applied to software development (code generation, code review, refactoring, writing automated tests, requirement analysis). * Experience with **Claude Sonnet 4\.5** or willingness to learn quickly. * Ability to apply **prompt engineering techniques** to: * debug and reason about code * generate high\-quality and consistent implementations * enforce architectural patterns and constraints * interpret technical and business requirements * Understanding of safe and responsible AI usage, including hallucination mitigation, validation steps, and code verification. * Basic familiarity with AI\-powered IDEs (Cursor, GitHub Copilot, JetBrains AI Assistant, etc.). **Preferred Qualifications** * BS/MS in Systems Analysis and Development, Computer Science, Computer Engineering, or equivalent fields.