Senior Fullstack Software Engineer (Java & React)
Senior fullstack engineer on a large-scale digital commerce platform built from microservices and micro-frontends: Java 25/Spring Boot 4/WebFlux backends, React/TypeScript frontends, Kubernetes/Docker deployments. Heavy emphasis on AI-assisted development (GitHub Copilot, coding agents) and legacy modernization.
- Compensation
- Not disclosed
- Location
- Warsaw, Masovian Voivodeship, pl
- Work setup
- Remote
- Seniority
- Senior
- Employment
- Not specified
- Experience
- Not specified
- Category
- Fullstack
- Posted
Skills
Must have
- Several years of professional web application development experience with strong backend expertise, working independently at senior level
- Strong practical knowledge of Java 8+ and Spring Boot, plus REST API design with JSON
- Strong understanding of reactive programming with hands-on Spring WebFlux, Project Reactor or comparable stack
- Hands-on frontend experience with React, TypeScript, JavaScript, HTML and NPM
- Experience with JUnit, Mockito, WireMock, Git, JPA/Hibernate and XML processing (XSLT, XPath, XQuery)
- Hands-on Kubernetes and Docker experience including deployment, operation, monitoring and troubleshooting
- Experience developing and evolving microservice-based, distributed systems, including long-running codebases
- Practical experience with AI-driven development (e.g. GitHub Copilot, coding agents, context management, spec-driven development)
- Regular use of AI coding agents, adapting prompts/skills and explaining how they improve the workflow
- Ability to own features from design through production and make sound technical decisions in a distributed architecture
- Proactive, analytical, quality-oriented approach with focus on continuous improvement
- Willingness to challenge approaches, contribute ideas, review code and share knowledge
- Ability to work effectively in an Agile, distributed and international environment
- English and Polish, written and spoken, minimum B2
Nice to have
- Experience with micro-frontend architectures
- Knowledge of Helm charts and Jenkins CI/CD pipelines
- Experience with headless or content-driven systems, particularly NEOS CMS
- Experience migrating legacy applications to modern platforms
- Experience with larger refactoring and technical debt reduction initiatives
- Previous experience in distributed, multinational and remote teams
- Knowledge of BDD and test automation beyond unit testing, e.g. Playwright
Full description
We are looking for a Senior Fullstack Software Engineer (Java & React) to join a team developing a large-scale digital commerce platform based on microservices and micro-frontends.
You will work end-to-end with Java 25, Spring Boot 4, Spring WebFlux, React, TypeScript and Kubernetes, building new features, integrating backend services and helping modernize the existing platform through legacy migration and technical debt reduction.
A key part of the project is AI-driven development, with coding agents and GitHub Copilot becoming part of everyday engineering. We are looking for someone who actively uses AI coding tools and is interested in shaping how they can improve software development.
Main tasks
- Develop and evolve a distributed online platform based on microservices and micro-frontends.
- Take end-to-end ownership of features, working across both backend and frontend within the same service.
- Build and maintain backend services using Java, Spring Boot and Spring WebFlux, including REST APIs and integrations with internal and backend systems.
- Develop frontend functionality using React, TypeScript, JavaScript, HTML and NPM.
- Work with content delivered through a CMS and related content delivery services.
- Implement new platform features and support the migration of legacy applications to the modern architecture.
- Improve the existing codebase through refactoring, technical debt reduction and resolution of long-standing technical issues.
- Contribute to the adoption of new API standards, including TM Forum Open APIs.
- Work with containerized applications using Kubernetes and Docker, including deployment, operation, monitoring and troubleshooting.
- Use AI coding agents and AI-assisted development workflows as part of your daily work and contribute to improving these practices within the team.
- Work on multiple initiatives of different sizes, from short tasks to larger projects.
- Participate in knowledge-transfer activities, keep technical documentation up to date and actively share knowledge with other developers.
Requirements
- Several years of professional experience in developing modern web applications, with strong backend expertise and the ability to work independently at Senior level.
- Strong practical knowledge of Java 8+ and Spring Boot, as well as REST API design with JSON.
- Familiarity with current versions of the Java/Spring ecosystem and a strong understanding of , supported by hands-on experience with .