Global Java Backend Developer - Public Sector APIs & Kafka

Billennium; Polska; On-site; PLN 120,000 - 160,000; Full time

Benefits offered by this job

Comprehensive benefits

Career growth

Global collaboration

Innovative environment

Team-building events

Job summary

Billennium seeks an experienced Java Backend Developer for a major European public‑sector client. You will contribute to designing and building large‑scale IT systems with Java, APIs, and relational databases.

The role focuses on scalable backend services, messaging with Kafka/JMS/ActiveMQ, and collaboration within an international environment using scaled Agile methodologies (SAFe or LeSS). English proficiency at B2/C1 is expected.

Qualifications

• Higher education in a technical field (ICT/STEM) with at least 3 years of university education confirmed by a diploma.
• At least 2 years of professional experience after graduation.
• At least 2 years of relevant professional experience in Java backend development.
• Proven experience in Java backend development and API design.
• Practical experience with relational databases (Oracle, MySQL).
• Experience with messaging technologies (Kafka, JMS, ActiveMQ).
• Experience delivering large-scale IT systems for the public sector.
• Experience with scaled Agile methodologies (SAFe or LeSS).
• Previous experience in international organisations and English proficiency (B2/C1).

Responsibilities

• Design and develop scalable backend solutions using Java.
• Design, develop, and maintain APIs and backend services.
• Work with relational databases (Oracle, MySQL).
• Implement messaging and event-driven solutions (Kafka, JMS, ActiveMQ).
• Contribute to large-scale IT systems for the public sector.
• Collaborate with international project teams.
• Follow scaled Agile methodologies (SAFe/LeSS).
• Contribute to analysis, design, implementation and continuous improvement of backend solutions.

Skills

Java backend development

API design

Scaled Agile (SAFe/LeSS)

International collaboration

Education

Higher education in ICT/STEM

Tools

Oracle

MySQL

Kafka

JMS

ActiveMQ

Job description

Billennium seeks an experienced Java Backend Developer for a major European public‑sector client. You will contribute to designing and building large‑scale IT systems with Java, APIs, and relational databases.

The role focuses on scalable backend services, messaging with Kafka/JMS/ActiveMQ, and collaboration within an international environment using scaled Agile methodologies (SAFe or LeSS). English proficiency at B2/C1 is expected.