Senior Software Engineer, Java

About the role

Upstream is seeking an enthusiastic Senior Software Engineer to join its Athens development team. You will work on mission‑critical Java applications, participating in all phases of the software lifecycle from concept to production support.

Key responsibilities

• Write well‑designed, testable, and efficient Java modules.
• Ensure designs comply with specifications and cover all implementation aspects.
• Prepare and produce releases of software components.
• Provide production support and troubleshoot issues.
• Create and review design documentation and give feedback on test plans.
• Drive continuous improvement by evaluating new technologies and presenting architectural recommendations.
• Mentor and coach junior developers.

Required profile

• BSc/MSc in Computer Science, Software Engineering or equivalent.
• 5+ years of professional experience designing and developing Java applications.
• Strong background in object‑oriented analysis and design.
• Experience with Spring Framework, JPA/Hibernate, and asynchronous messaging (RabbitMQ, Kafka).
• Proficiency in designing HTTP web services and solid SQL/RDBMS knowledge.
• Familiarity with Maven, Git and Continuous Delivery principles.
• Additional experience with NoSQL databases (Redis, Elasticsearch, Couchbase), caching solutions (Hazelcast, EhCache) and microservices architectures is a plus.

Required skills

• Java
• Spring Framework
• JPA / Hibernate
• RabbitMQ
• Kafka
• HTTP web services
• SQL and relational databases
• Maven
• Git
• Continuous Delivery
• Redis (optional)
• Elasticsearch (optional)
• Couchbase (optional)
• Hazelcast (optional)
• EhCache (optional)
• Microservices architecture