Fullstack Java + React Developer (Java/Spring Boot/React + AI Tooling) - Portuga

ABOUT THE OPPORTUNITY We are looking for two Full Stack Engineers — one Senior and one Mid-level — to help build, evolve and operate scalable digital products that deliver real value to customers and internal teams. You will work across the full stack, contributing throughout the software development lifecycle: from API design and distributed backend services to modern, accessible web interfaces. This role combines strong hands-on engineering across the Java and JavaScript ecosystems with the practical use of approved AI-assisted development tools as part of a modern engineering workflow. You will own features end to end, in a team where technical decisions are discussed rather than dictated. PROJECT & CONTEXT The client is a well-established player in the retail sector, operating large-scale, high-traffic digital platforms where performance, reliability and scale are daily engineering concerns. The ecosystem is built on distributed, containerised services with a modern React/Next.js frontend layer and a mature CI/CD and observability culture. AI tooling is an established part of how the team works — not an experiment — and engineers are expected to use it critically, validating and improving what it produces. You will join a product-oriented team with a stable roadmap and a platform used by a large customer base. WHAT WE'RE LOOKING FOR (Required) AI-assisted engineering - Practical experience using AI tooling to support development activities: code generation and refactoring, test creation and automation, documentation generation, code analysis and review, and technical investigation - Ability to review, validate and improve AI-generated output to ensure quality, security and maintainability Backend - Strong commercial experience developing software with Java (recent versions — Java 17 LTS or above) and Spring Boot 3.x - Experience building and operating distributed systems, RESTful APIs and microservices - MySQL 8 — schema design, query optimisation and performance tuning - AWS — building, deploying and maintaining cloud-native applications Frontend - Strong commercial experience with JavaScript and TypeScript - Experience building modern web applications with React 18 - Strong understanding of web performance, accessibility and responsive design Engineering practices - Strong understanding of software engineering best practices, testing, code quality and maintainable code - Strong understanding of CI/CD practices and modern software delivery approaches - Experience with containerisation technologies - Understanding of infrastructure, monitoring and observability practices - Strong problem-solving skills and the ability to contribute effectively in a collaborative, cross-functional team - Fluent English, spoken and written (working language of the project) NICE TO HAVE (Preferred) - Next.js in production environments - Kubernetes and container orchestration platforms - Apache Kafka or other event-streaming technologies - Modern observability and monitoring tooling - Experience in large-scale digital, retail or eCommerce environments - AWS certifications - Portuguese language skills Compensation: €2000 – €2600/month net, depending on experience and seniority level. Why HumanIT people stay (4.4 Glassdoor, 89% recommend) - 15th month salary - Health insurance covering your family - Birthday off - Mobility program for digital nomads - Real work-life balance Originally posted on Himalayas