Senior Java Developer

Quick Facts

• Contract: B2B

• Rate: up to 190 PLN/h net + VAT

• Project start: December 2026

Description

We are looking for a Senior Java Developer responsible for designing and developing REST APIs and integration services based on Java and Spring Boot. The role also includes integration with mainframe systems, support for deployments on PaaS and container environments, and sharing technical knowledge with the team.

Role Responsibilities

• Design and develop REST APIs using Java and Spring Boot

• Create APIs using contract-first approach with OpenAPI/Swagger

• Develop integration and transport services connecting digital solutions with mainframe systems via IBM MQ

• Map and validate data, handle errors, and ensure reliable message exchange

• Support deployments on PaaS platforms and in containerized environments

• Participate in a potential migration from single-cluster to multi-cluster architecture

• Mentor and train other developers

• Prepare clear technical handovers and documentation

Requirements

• Minimum 5 years of software development experience

• Very good, hands-on knowledge of Java and Spring Boot

• Experience designing and implementing REST APIs

• Practical knowledge of OpenAPI/Swagger and API contracts

• Experience working with IBM MQ or similar communication technologies

• Knowledge of integration patterns and asynchronous communication

• Experience with container environments and/or PaaS platforms

• Ability and willingness to mentor, train, and share knowledge

• Fluent English (spoken and written) for daily collaboration with the team in Denmark

Benefits

• Access to local and international projects (clients in France, Germany, Portugal, the UK, and Benelux)

• Career development support: trainings, technical certificates, conferences, funded language and soft-skill trainings up to 2,000 PLN

• Flexibility: choice of employment model (employment contract or B2B)

• Referral bonus up to 6,000 PLN

• Fully paid Medicover healthcare card

• Multisport card

• Regular integration events and gifts

• Mobility program

• Long-term cooperation