Full-Stack Developer – Java, Spring Boot & React

Location: Luxembourg or Prague
Start date: As soon as possible
Employment type: Freelance

About the role

We are looking for an experienced Full-Stack Developer to design, build, and maintain modern, scalable applications. You will work across the technology stack, with a primary focus on Java and Spring Boot backend services and React-based user interfaces.

The role involves developing RESTful APIs, integrating databases and messaging systems, containerising applications, and supporting deployments to an OpenShift environment. You will collaborate with developers, architects, DevOps engineers, product owners, and other stakeholders throughout the software development lifecycle.

Key responsibilities:

Backend development

• Design, develop, test, and maintain backend services using Java and Spring Boot.

• Build secure, reliable, and well-documented RESTful APIs.

• Translate business and technical requirements into maintainable software solutions.

• Design and optimise data models, database queries, and persistence layers.

• Integrate applications with relational databases, preferably PostgreSQL.

• Develop event-driven and asynchronous processes using Kafka or similar messaging technologies.

• Apply appropriate error handling, logging, monitoring, and API versioning practices.

• Write clean, modular, reusable, and well-tested code.

• Investigate production issues and implement sustainable fixes.

Frontend development

• Build responsive and user-friendly web interfaces using React.

• Develop reusable components and maintain a consistent frontend architecture.

• Integrate frontend applications with RESTful backend services.

• Manage application state, user input, validation, and error handling.

• Work with designers and business stakeholders to translate requirements into intuitive user experiences.

• Ensure compatibility, accessibility, performance, and maintainability across the application.

DevOps and delivery

• Create and maintain Docker images and container configurations.

• Support the deployment and operation of applications on OpenShift or a comparable container orchestration platform.

• Contribute to continuous integration and continuous delivery processes.

• Manage source code and collaborate through Git and GitHub.

• Configure and maintain application build processes using Maven or Gradle.

• Participate in code reviews, release activities, troubleshooting, and technical documentation.

• Follow secure software development, configuration management, and deployment practices.

Required skills and experience

• Strong commercial software development experience using Java.

• Strong practical knowledge of Spring Boot and the wider Spring ecosystem.

• Proven experience designing and developing RESTful APIs.

• Strong proficiency in React and modern JavaScript or TypeScript.

• Experience working with relational databases and SQL.

• Good understanding of database modelling, transactions, indexing, and query optimisation.

• Practical experience with Git-based development workflows.

• Strong knowledge of Docker and containerised application development.

• Experience with Maven or Gradle.

• Familiarity with automated testing across backend and frontend applications.

• Understanding of software engineering principles, design patterns, and clean-code practices.

• Ability to analyse technical problems and communicate solutions clearly.

• Professional working proficiency in English.

Desirable skills and experience

• Hands-on experience with PostgreSQL.

• Experience with Kafka or another distributed messaging platform.

• Experience deploying and operating applications on OpenShift.

• Knowledge of Kubernetes concepts, including deployments, services, configuration, secrets, and health checks.

• Experience building or maintaining CI/CD pipelines.

• Familiarity with application security, including authentication, authorisation, and secure API development.

• Experience with monitoring, centralised logging, and application performance diagnostics.

• Knowledge of microservices, event-driven architectures, and distributed systems.

• Experience working in an Agile or Scrum delivery environment.

What we are looking for

• A pragmatic developer who balances delivery speed with quality and maintainability.

• A collaborative team member who communicates effectively with both technical and non-technical stakeholders.

• Someone comfortable taking ownership of features from initial design through deployment and production support.

• A proactive problem-solver who can work independently while contributing constructively to team decisions.

• A commitment to testing, documentation, code quality, and continuous improvement.