Senior Developer Fullstack (Java/React)

This position is listed on behalf of a partner company, who manages all applications and next steps. Our partner is looking for a Senior Developer Fullstack (Java/React) based in Brazil. This is an opportunity for a senior full-stack engineer to build and evolve modern applications within a cloud-based microservices ecosystem. You will work across both backend and frontend, transforming business and technical requirements into robust, scalable solutions. The role combines hands-on development with architectural thinking, troubleshooting, and continuous technical improvement. You will contribute throughout the development lifecycle, from technical refinement and implementation through testing and deployment. Strong engineering practices around quality, security, observability, automation, and maintainability are central to the role. You will also help elevate the wider team by sharing knowledge, challenging assumptions, and promoting effective development practices. The environment values autonomy, collaboration, technical maturity, and the ability to make sound decisions in situations of ambiguity. Develop end-to-end solutions across backend and frontend, using Java/Spring Boot and React within a cloud-native microservices environment. Build and maintain REST APIs, microservices, business logic, integrations, and synchronous and asynchronous processing. Develop modern React interfaces, reusable components, state management solutions, and integrations with backend APIs. Translate business and technical requirements into simple, scalable, sustainable, and maintainable technical solutions. Apply software architecture principles including Clean Architecture, Domain-Driven Design (DDD), SOLID, design patterns, and established engineering practices. Work with distributed systems, APIs, events, messaging, and communication between services. Contribute throughout the full development lifecycle, including technical refinement, implementation, automated testing, code review, and deployment. Support CI/CD pipelines, build and deployment automation, traceability, and integration with quality and security tools. Investigate production incidents, analyze logs, metrics, and traces, perform troubleshooting, and identify root causes. Identify technical risks, bottlenecks, vulnerabilities, and technical debt, proposing practical improvements. Apply security best practices throughout the software development lifecycle, including identifying and addressing vulnerabilities. Contribute to the technical evolution of the team through knowledge sharing, mentoring, and promotion of good engineering practices. Use AI-powered development tools responsibly to increase productivity, quality, and effectiveness in development and technical investigation. Requirements: Strong professional experience developing backend solutions with Java and Spring Boot , including REST APIs, microservices, business rules, integrations, and synchronous/asynchronous processing. Solid hands-on experience with React , including interfaces, reusable components, state management, and API integration. Strong understanding of application architecture, including Clean Architecture, DDD, SOLID, design patterns , and software engineering best practices. Experience working with distributed systems, APIs, events, messaging, and service-to-service communication. Practical experience with AWS , particularly services such as Lambda, SQS, SNS, S3, ECS/EKS, and other services used in cloud-native solutions. Experience with CI/CD , including pipelines, build and deployment automation, traceability, and quality/security integrations. Experience creating and maintaining automated unit, integration, and contract tests . Experience with Docker and Kubernetes , including EKS, OpenShift Container Platform (OCP), or equivalent technologies. Strong troubleshooting and observability skills, including working with logs, metrics, traces, monitoring, and production environments. Understanding of applicati