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-skilledJava Full-Stack Developerswith 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 RoleAs 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 usingAI-assisted development workflows, LLMs, and prompt engineering to accelerate delivery while maintaining high quality.ResponsibilitiesDevelop 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.UseAI-assisted workflowsto generate code, improve documentation, and create automated tests.Participate in agile ceremonies and work effectively with distributed teams.Required ExperienceStrong hands-on experience withJava (Spring Boot),Node.js, andReact.Experience withPostgreSQLand relational data modeling.Familiarity withSecurity / DevOps / Cloudpractices.Knowledge ofGitHub CI/CD pipelines, versioning, and workflow automation.Practical usage ofGitHub Advanced Security(CodeQL, secret scanning, dependency checks).Experience withAWS IAM(roles, policies, permission boundaries).Experience deploying or maintaining workloads onEC2,RDS, andSQS.Working knowledge of LLM capabilities applied to software development (code generation, code review, refactoring, writing automated tests, requirement analysis).Experience withClaude Sonnet 4.5or willingness to learn quickly.Ability to applyprompt engineering techniquesto:debug and reason about codegenerate high-quality and consistent implementationsenforce architectural patterns and constraintsinterpret technical and business requirementsUnderstanding 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 QualificationsBS/MS in Systems Analysis and Development, Computer Science, Computer Engineering, or equivalent fields.