Java Software Engineer

About the role

Upstream is seeking a motivated Java Software Engineer to join its Athens development team. You will work on mission‑critical, high‑volume applications that support mobile marketing automation for global operators and brands.

Key responsibilities

• Develop high‑volume, low‑latency Java applications for mission‑critical systems.
• Write well‑designed, testable, and efficient software modules.
• Ensure designs meet specifications and that specifications cover all implementation aspects.
• Create and review design documentation and provide feedback on test plans.

Required profile

• BSc/MSc in Computer Science, Software Engineering or equivalent.
• 3+ years of professional experience designing and developing Java applications.
• Strong background in object‑oriented analysis and design.
• Excellent communication skills and ability to work in a collaborative team.
• Analytical thinker with attention to detail and ability to multitask in a dynamic environment.

Required skills

• Java
• Spring Framework
• JPA/Hibernate
• JEE
• SQL and relational database concepts
• HTTP APIs
• Maven, Git and CI/CD principles
• Asynchronous messaging (RabbitMQ, Kafka) – preferred
• Microservices architecture – preferred
• NoSQL/ caching technologies (Redis, Elasticsearch, Hazelcast, EhCache) – preferred

What we offer

• Competitive base salary
• Benefits package aligned with candidate qualifications and skills