Software Engineer, Java

The Company Upstream is a global leader in mobile marketing automation and digital service innovation, enabling Mobile Network Operators (MNOs) and brands to grow revenue, improve customer engagement and succeed in the digital economy. With over two decades of experience and operations spanning 45+ markets across Africa, Latin America, Asia, Europe, and the Middle East, we are a trusted partner to more than 60 MNOs worldwide. Headquartered in Athens, Greece, and with regional hubs in London, Dubai, Johannesburg, Lagos, São Paulo and Rio de Janeiro, Upstream combines global expertise with deep local insight. Our end-to-end approach encompasses strategy, creative development, technical deployment, campaign execution, and ongoing optimization, ensuring seamless, scalable, and performance-driven service delivery. The role We are looking for an enthusiastic Software Engineer, Java, to join our Software Development team in Athens, Greece. You will be part of a very competent team that works on mission - critical applications, contributing to all phases of the development process. You will be responsible for Java application development, supporting business objectives while providing expertise in the full software development lifecycle, from concept and design to testing. Your main responsibilities will be: Develop on high-volume, low-latency applications for mission-critical systems, delivering high-availability and performance Write well-designed, testable, efficient software modules Ensure designs comply with specifications and that specifications cover all needed aspects of the implementation Create/review design documentation and provide feedback on test plans Requirements BSc/MSc in Computer Science, Software Engineering or equivalent 3+ years of full time professional experience in designing and developing applications using the Java ecosystem Solid background in Object Oriented Analysis and Design Experience with popular Java frameworks and technologies such as Spring Framework, JPA/Hibernate, JEE Good knowledge of SQL and RDBMS concepts Experience with HTTP APIs Basic understanding of concurrency concepts Working knowledge of Maven, Git and CI/CD principles Experience in the following will be extra appreciated: Asynchronous messaging technologies, such as RabbitMQ, Kafka Horizontally scalable, distributed, microservices architectures NoSQL databases such as Redis, Elasticsearch Caching technologies, such as Hazelcast, EhCache You will be an excellent fit for our team if you are: Strong team player with good communication skills Eager to work with leading-edge technologies Analytical thinker with attention to detail Reliable and dedicated professional with clear thinking and strong attention to detail Able to multitask and thrive in a dynamic environment as well as balance and prioritize activities to ensure critical items are addressed Benefits We offer a competitive base salary and benefits, directly dependent on the candidate's qualifications and skills. The real excitement comes from working closely with a dynamic, smart, agile and highly motivated team in a competitive and fast paced environment. Follow us on LinkedIn and stay updated on our latest news Upstream is an equal opportunity employer. The Company does not discriminate on the basis of race, colour, creed, pregnancy, religion, gender, national origin, age, disability, marital, or any other legally protected status. The Company also makes reasonable accommodations for disabled employees. Finally, the Company prohibits the harassment of any individual based on their protected status. This policy applies to all areas of personnel actions including recruitment, hiring, training, promotion, compensation, benefits, transfer, and social and recreational programs.