Senior Backend Developer (Java / .NET)

Quick Facts

• Role: Senior Backend Developer (Java / .NET)

• Focus: Backend services and REST APIs for client-facing portal applications

• Work model: B2B contract; Hybrid (Warsaw, 3 days/week in office)

• Start: ASAP / flexible

Description

Join an international team building and maintaining scalable backend services and REST APIs for client-facing portal applications. You will develop backend services using Java (Spring Boot) or .NET Core, design integrations with relational and NoSQL databases, and collaborate with frontend teams. You will also deliver containerized, secure, well-tested solutions using CI/CD pipelines.

Responsibilities

• Develop and maintain backend services and REST APIs (Java Spring Boot or .NET Core)

• Design and integrate solutions with relational and NoSQL databases

• Collaborate with frontend teams for seamless integrations

• Build and deploy applications in containerized environments (Docker, Kubernetes, OpenShift)

• Implement secure coding practices, automated testing, and CI/CD pipelines

• Optimize performance, scalability, and reliability

• Troubleshoot production issues and support application stability

• Participate in Agile ceremonies and technical design discussions

Requirements

• 8+ years of backend development experience

• Strong expertise in Java or .NET

• Hands-on experience building and consuming REST APIs

• Experience with Docker, Kubernetes, or OpenShift

• Solid SQL and database knowledge

• Experience with CI/CD pipelines and automated testing

• Strong communication and teamwork skills

Benefits

• B2B contract via Experis

• Hybrid work model (Warsaw, 3 days/week in the office)

• Long-term international projects

• Medicover healthcare package

• Multisport card

• Group life insurance