We are looking for a Senior Full Stack Engineer with a strong frontend focus (React + Java) for our partner, a growing software company based in Spain.

Our partner combines product development with client-facing engineering work, delivering software solutions for enterprise customers.

You will join a team working on a live production product for a large US healthcare enterprise. The platform is currently undergoing a significant architectural modernization: an existing Ruby middleware layer is being removed, allowing the React frontend to communicate directly with the core Java APIs, while the system is also moving toward a more secure access architecture.

The role is primarily focused on React and frontend engineering, while requiring the ability to work across the stack with Java and Spring Boot when needed.

The project has an important upcoming release, so we are looking for an experienced engineer who can understand an existing production system and become productive quickly.

This is a full-time remote contract position with an initial commitment of at least six months and the possibility of long-term extension.

Responsibilities

* Design, develop, and maintain production frontend applications using React and TypeScript.

* Build scalable, reusable, and maintainable frontend components and application architecture.

* Contribute to the migration away from the existing middleware layer and integrate the React application directly with Java APIs.

* Deliver end-to-end product features across the React frontend and Java/Spring Boot backend when required.

* Work with REST APIs and complex backend integrations.

* Participate in the platform’s migration toward a more secure and modern access architecture.

* Contribute to frontend architecture, technical design, performance, and code quality decisions.

* Understand and improve an existing production codebase while maintaining stability.

* Work with AWS-based production environments.

* Collaborate closely with backend engineers, QA, and other members of the product team.

* Participate in Agile ceremonies and planning activities.

* Use AI-assisted development tools as an integral part of the engineering workflow.

Requirements

Technical Skills

* 6+ years of professional software engineering experience.

* Strong hands-on experience with React and TypeScript.

* Strong understanding of modern frontend architecture, component design, state management, performance optimization, and API integration.

* Professional experience with Java and Spring Boot and the ability to contribute to backend development.

* Proven experience building and maintaining production-grade web applications.

* Strong experience integrating frontend applications with REST APIs and backend services.

* Experience working with existing production systems and complex codebases.

* Hands-on experience with AWS and cloud-based production environments.

* Experience with Docker, CI/CD pipelines, and modern cloud-native development practices.

* Solid understanding of software architecture and system design.

* Ability to ramp up quickly and work effectively within an established engineering environment.

AI & Modern Engineering Expectations

* Strong hands-on experience using AI-powered development tools such as Claude Code or similar as part of the day-to-day engineering workflow.

* Up-to-date understanding of modern AI capabilities and their practical application in software development.

* Ability to use AI tools to accelerate development, improve code quality, support technical decisions, and increase engineering productivity.

* Experience with Spec-Driven Development (SDD) or similar methodologies that enable AI-native development workflows.

* Ability to identify opportunities where AI can add meaningful value to the product and its users.

* Comfortable working in an engineering environment where AI-assisted development is an integral part of the software development lifecycle.

Communication

* English level B2 or higher.

* Ability to communicate technical concepts clearly to both technical and non-technical stakeholders.

* Strong written communication and documentation skills.

* Comfortable working within distributed international teams.

Personal Qualities

* Strong ownership mentality and proactive approach.

* Ability to understand an existing system and become productive quickly.

* Ability to identify issues early and drive solutions independently.

* Open-minded and adaptable when evaluating technologies and approaches.

* Focus on code quality, maintainability, and long-term sustainability.

* Collaborative attitude and strong teamwork skills.