Senior Backend Developer

Billennium is a global technology company with over 20 years of experience, committed to innovation and empowering businesses. As an employer, we offer a supportive, growth-focused environment where collaboration and creativity thrive. Join us to shape the future of technology together!

We are looking for an experienced Senior Backend Developer who will join a long-term project for our client in the banking industry.

This position follows a hybrid work model, with 3 days per week in the Warsaw office.

What you will do:

• Develop and maintain backend services and RESTful APIs using Java or .NET.
• Design data models and integrate with relational and NoSQL databases to support portal functionality.
• Collaborate with front-end developers to define API contracts and ensure seamless integration.
• Build, deploy, and manage services in containerized environments using Docker, Kubernetes, or OpenShift.
• Implement secure coding practices, automated testing, and CI/CD pipeline integration.
• Optimize application performance, scalability, and reliability.
• Troubleshoot and resolve production issues, participating in on-call and support rotations as needed.
• Contribute to Agile ceremonies, sprint planning, and technical design discussions.

What are we looking for:

• 8+ years of backend software development experience with strong expertise in Java or .NET.
• Strong hands-on experience with Spring Boot or .NET Core.
• Proven experience building and consuming RESTful APIs.
• Experience working with containerized applications and orchestration platforms such as Docker, Kubernetes, or OpenShift.
• Strong SQL and database experience, including relational data modeling and query optimization.
• Familiarity with CI/CD pipelines, automated testing, and software delivery best practices.
• Experience with messaging and event-driven architectures (e.g., Kafka, MQ) is a plus.
• Previous experience in financial services, fund administration, or transfer agency environments is an advantage.
• Exposure to cloud-native development practices is preferred.

Perks and benefits (our offer):

• Comprehensive benefits
  • enjoy Udemy for Business, private medical care, Multisport card, veterinary package, language lessons, and shopping vouchers.
• Flexibility
  • adaptable working hours and remote/hybrid work options to suit your lifestyle & location.
• Career growth
  • access opportunities for professional development and learning, including perks related to our official partnerships with global IT giants: Microsoft, AWS, Snowflake, Salesforce & more.
• Global collaboration
  • work with a diverse, international team.
• Innovative environment
  • be part of a forward-thinking and growth-oriented workplace.
• Engaging community
  • work with passionate professionals and participate in team-building events, hackathons, and CSR initiatives to make an impact beyond work.
• Team-building events including our company tradition (annual company event in Mazury).
• A pleasant surprise to start your journey with us in the form of a welcome pack.