Back End Developer

As a Senior Fullstack Developer (backend-focused), you will play a key role in the modernization effort by developing APIs that enhance user experience and enable scalable future development.

The team is responsible for building and improving a range of services operating in both microservice and monolithic architectures. The project follows Domain-Driven Design (DDD) and port-adapter architecture principles. Most services use a reactive stack, with selected integrations involving Angular-based UI.

Responsibilities

• Develop new features supporting platform modernization
• Implement changes required for maintenance and regulatory compliance
• Work on core domains such as:
• Accounts
• Payments
• File transfers
• Local and international services
• Collaborate with developers, Product Owner, architects, analysts, and QA engineers

• Minimum 6 years of experience with Java
• Experience in building APIs
• Familiarity with reactive programming
• Strong knowledge of: Spring, Hibernate, Cucumber
• Experience with: SQL, REST, microservices, Git
• Understanding of SOLID principles and design patterns
• Experience working in Agile environments
• Fluent English

• A full-time contract (B2B also possible).
• Stable and long-term cooperation.
• A well-defined career path at the European leader in engineering & IT consulting.
• Participation in company conferences, trainings, workshops, and integration meetings.
• Certification and training opportunities.
• Opportunity to relocate and work in different ALTEN Polska branches.
• After project completion, the opportunity to engage in a subsequent project within the company.
• Introduction and cooperation with a dedicated Business Development Manager.

Benefits (Contract of Employment)

• Medicover medical care.
• Medicover dental care.
• Medicover Benefits platform / Medicover Sport card.
• Employee referral program.
• Layette for a newborn employee's child.
• Group life insurance.
• Pension scheme.

WE ARE A WORLD LEADER IN ENGINEERING AND IT SERVICES. At ALTEN, we see our specialists as architects - today's designers of tomorrow's world. As a leader in Engineering and IT Services, we support companies in their technological and sustainable transformation. OVER 57,400 EMPLOYEES IN 30+ COUNTRIES, TO SUPPORT MORE THAN 6,500 CLIENTS WORLDWIDE. We operate in all sectors: Aeronautics, Space, Defence, Security & Naval, Automotive, Rail & Mobility, Energy & Environment, Life Sciences & Health, Industrial Equipment & Electronics, Telecoms, Banking, Finance & Insurance, Retail, Services & Medias, Public Services & Government. We carry out complex and highly technical projects throughout the value chain of the most prestigious companies worldwide. Our motto: Building Tomorrow's World Today! Hybrid Model - Warsaw/Tricity About the project Join a team working on a next-generation digital banking platform for corporate clients. The project focuses on modernizing existing solutions and building a new system that improves access to key financial services such as account management, domestic and international payments, and liquidity monitoring. The goal is to create an intuitive, scalable digital channel (including mobile) that enables businesses to efficiently manage their finances and user permissions.