Java Full Stack Developer

About this role

Location: Vienna (1–2 days on-site per week during onboarding, then 2-4 day per month; otherwise fully remote) Start: ASAP | Duration: 12 months (extension possible) | Workload: 100% Language: English (must-have) + German (

nice to have

• )
• We are seeking an experienced Java Full Stack Developer with a strong focus on backend development to join our agile team.

Your role will involve designing and developing APIs, implementing microservice-based architectures, integrating with databases, and contributing to frontend development using JavaScript/TypeScript with React or Angular. You will collaborate closely with cross-functional teams in an agile environment. Experience in the telecommunications sector is a strong plus.

• Why Join Us?
• Work on impactful, enterprise-grade solutions
• Agile, collaborative work environment with international teams
• Opportunity to influence architecture and technology decisions
• Engagement in a technically demanding, modern Java backend / Fullstack environment
• Interested?
• Please send your updated CV including availability and hourly rate expectations. We look forward to hearing from you!
• Please contact me by email at elena.kahraman@qualysoft.com, or via LinkedIn. Thank you for your understanding! +43 699 14402417

Key Responsibilities

• Design, develop, and maintain backend services using Java, Spring, and Spring Boot
• Implement and integrate REST APIs for internal and external systems
• Conduct unit testing using JUnit to ensure code quality
• Manage builds and dependencies with Maven
• Work with PostgreSQL, ideally including JSONB
• Design and develop scalable, maintainable microservice architectures
• Collaborate closely with product owners, architects, developers, and DevOps teams
• Contribute to the continuous improvement of development processes and tools
• Ensure solutions meet performance, stability, and security standards
• Contribute to the frontend using JavaScript/TypeScript and React or Angular
• Work with technologies from the Apache ecosystem where applicable (e.g. for services, integration, or tooling)

Required Skills & Experience

• Proven professional experience in backend development with Java (Java 21 preferred)
• Strong knowledge of Spring and Spring Boot
• Experience with REST API development and integration
• Proficiency in JUnit for unit testing
• Experience in Maven build management
• Solid knowledge of PostgreSQL (JSONB is a plus)
• Strong background in microservice architecture design and implementation
• Experience with frontend development using JavaScript/TypeScript and React or Angular
• Familiarity with Apache-based technologies in a typical Java backend stack
• Agile mindset and experience working in Scrum/Kanban teams
• Excellent command of English (spoken & written)

Nice to Have

• Kubernetes & Helm for deployment and orchestration
• SOAP service integration experience
• Experience with Graylog for logging and monitoring
• Telecommunications industry knowledge (big plus)
• Knowledge of Kafka , Apache