Senior Backend Developer (Java / .NET)

Backend Developer (Java or.NET)

Location: Warsaw (Hybrid - 3days per week in the office)
Start Date: ASAP / Flexible
Cooperation Model: B2B via Experis

We are looking for an experienced Backend Developer to join an international team building and maintaining scalable backend services and APIs powering client-facing portal applications.

Responsibilities

• Develop and maintain backend services and REST APIs using Java (Spring Boot) or .NET Core .
• Design and integrate solutions with relational and NoSQL databases.
• Collaborate closely with frontend teams to deliver seamless integrations.
• Build and deploy applications in containerized environments using Docker, Kubernetes, or OpenShift .
• Implement secure coding practices, automated testing, and CI/CD pipelines.
• Optimize application 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.

Nice to Have

• Experience with Kafka, MQ, or other messaging technologies.
• Cloud‑native development experience.
• Background in financial services, fund administration, or transfer agency environments.

What We Offer

• B2B contract via Experis
• Long‑term international projects
• Medicover healthcare package
• Multisport card
• Group life insurance