Backend developer Java

Together with our Business Partner, a leading company in the telecommunications industry, we are looking for an experienced specialist to implement projects as a Java Developer. The project involves the development of backend services and integrations in an event-driven architecture, maintaining the stability of the production environment, and participating in the technological transformation towards the Node.js/TypeScript ecosystem.

Nice to have: Node.js / TypeScript (Express, Fastify, NestJS)

✨ WE OFFER A new way to apply with the AI Recruiter (AIR) - during the process, you can talk to a virtual recruiter 24/7, without waiting for a call. The final decision is always made by the Project Manager. Cooperation in a project-based model, with settlement based on stages and acceptance protocols for individual deliverables. Support from Connectis regarding administrative and billing matters related to the cooperation. Participation in industry events and technological meetups. 5,000 PLN for referring friends to our projects. Flexible B2B cooperation form for projects carried out for a renowned Partner in the telecommunications industry. A fast and remote process.

Thank you for all your applications. We would like to inform you that we will contact selected individuals.

13314/IW

Daily tasks

• Development and modernization of backend services implemented in Java 21+ and Spring Boot 3.x.
• Designing, documenting, and versioning REST API interfaces compliant with the OpenAPI standard.
• Implementing system integrations and asynchronous flows in an event-driven architecture (message-based communication).
• Implementing authentication and authorization mechanisms based on Spring Security, OAuth2, and JWT.
• Ensuring the continuity of production solutions: monitoring, diagnostics, and troubleshooting the causes of incidents.
• Covering delivered deliverables with unit and integration tests as part of the acceptance protocol.
• Co-creating the direction of technological migration towards the Node.js/TypeScript ecosystem.
• Utilizing AI-class tools to optimize the software development process and shorten the time to deliver results.
• In a broader scope of services (senior level): designing distributed systems, developing engineering standards, and providing substantive support to less experienced specialists.
• Technical consultations and architectural agreements with technical leads and architects on the Business Partner's side.

Requirements

🔍 REQUIRED COMPETENCIES: Strong, commercially proven knowledge of Java 21+ and Spring Boot 3.x. Independent design of REST API / OpenAPI and implementation of integrations between systems. Practical knowledge of Spring Security, OAuth2, and JWT. Experience working with MongoDB or another NoSQL database. Testing discipline: independent creation of unit and integration tests as a standard, not an option. Knowledge of observability tools (monitoring, logging, production event analysis). Proficiency in Maven or an equivalent build tool. Minimum 4 years of commercial backend experience (mid level) or minimum 6 years (senior level) along with experience in designing distributed systems, handling production incidents, leading technological migrations, and developing less experienced specialists. English language at a minimum B2 level, enabling independent work with technical documentation and ongoing communication in the project. Production Engineer mindset: responsibility for the working production system, not just the delivered code. AI First approach: active use of AI tools when building the product and optimizing your own service delivery process. Independent selection of methods, tools, and technical solutions adequate for service implementation, without the need for substantive supervision. Efficient navigation in complex, legacy systems, a pragmatic approach to modernization, and a readiness to challenge the status quo.

Must have: Java, REST API, OpenAPI, Spring Boot, MongoDB, Maven, AI, Spring Security, Oauth2, JWT, Observability, Kafka, GraphQL, TypeScript

Nice to have: Docker, Kubernetes, Node.js, RabbitMQ, Terraform