Java Backend Engineer — Public Sector API & Microservices

Billennium; Warszawa; On-site; PLN 140,000 - 200,000; Full time

Benefits offered by this job

Udemy for Business

Private medical care

Multisport card

Language lessons

Shopping vouchers

Global partnerships

Team events

Hackathons

CSR initiatives

Mazury company event

Job summary

Billennium is seeking an experienced Java Backend Developer for a major European public-sector project. The role focuses on developing scalable backend systems using Java, APIs, and relational databases, in an international setup.

You will design, implement, and improve backend services, work with Oracle/MySQL and messaging systems like Kafka, JMS, ActiveMQ, and collaborate across cross-border teams using scaled Agile approaches (SAFe/LeSS). English proficiency is required.

Qualifications

• Higher education in ICT/STEM with a diploma.
• At least 2 years of professional experience after graduation.
• Experience in Java backend development.
• Proven API design and development experience.
• Experience with Oracle and MySQL databases.
• Experience with Kafka, JMS, and ActiveMQ messaging.
• Experience delivering large-scale IT systems for the public sector is a plus.

Responsibilities

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

Skills

Java

APIs

SAFe

LeSS

English (B2/C1)

International collaboration

Education

Higher education in ICT/STEM with diploma

Tools

Kafka

JMS

ActiveMQ

Oracle

MySQL

Job description

Billennium is seeking an experienced Java Backend Developer for a major European public-sector project. The role focuses on developing scalable backend systems using Java, APIs, and relational databases, in an international setup.

You will design, implement, and improve backend services, work with Oracle/MySQL and messaging systems like Kafka, JMS, ActiveMQ, and collaborate across cross-border teams using scaled Agile approaches (SAFe/LeSS). English proficiency is required.