Senior Java Developer | FinTech e-Payments Solution, Remote

• 🚀 Are you excited to work with cutting-edge Java 20 and Spring Boot technology, developing systems for one of the most innovative electronic payments companies in Greece?
• 💻 Do you want to contribute to building high-quality, secure, and high-performance backend services where clean code and attention to detail matter?
• 🌍 Are you looking for a role with flexible work options while being part of a dynamic team driving innovation in the fintech industry?

ManpowerGroup Greece, on behalf of our client a well-established leader in the electronic payments industry is seeking an experienced Senior Java Developer to join their growing team.

📌 Location: Athens Greece  

📍 Working Model: Fully Remote (you need to be based in Greece and holder of a valid EU Work Permit)

🖋️ You will be reporting to: CTO

What you will do:

As a Senior Developer, you will play a key role in designing, developing, and maintaining robust backend services using Java and Spring Boot. You will build and optimize RESTful APIs, manage PostgreSQL databases, and deploy applications on AWS to ensure high performance, scalability, and reliability. In addition, you will guide technical decision-making and contribute to architectural discussions while collaborating within a cross-functional team to deliver secure and maintainable solutions. This role emphasizes clean code, scalable systems, and real-world problem solving, providing an opportunity to shape the backend architecture in a dynamic environment.

Your main responsibilities will be:

• Designing and developing backend systems using Java (20+), Spring Boot, and REST APIs.
• Leading engineering efforts on system design, architecture, and scalability
• Building and managing long-running synchronous/asynchronous workflows, applying strategies like decoupling, batching, and async execution
• Ensuring fault tolerance, data consistency, and concurrency handling in distributed environments
• Applying messaging patterns with Kafka: queues, topics, point-to-point, and pub-sub
• Working with idempotent consumers, retries, and event/message processing.
• Designing and maintaining resilient REST APIs that persist state and recover gracefully from failures
• Implementing database transactions, ACID principles, and multiple isolation levels with PostgreSQL
• Utilizing modern Java concurrency tools including virtual threads and traditional threads
• Collaborating cross-functionally with product managers and other engineering teams
• Contributing to documentation and knowledge sharing

• BSc/MSc in Computer Science, Software Engineering, or a related field
• 5+ years of professional software development experience in Java
• Strong proficiency in Java 20+, Spring Boot, REST APIs
• Deep understanding of backend architecture patterns, including hexagonal architecture
• Expertise in messaging systems (Kafka, queues, topics)
• knowledge with AWS cloud services
• Solid knowledge of PostgreSQL and database design
• Strong grasp of concurrency, data consistency, and fault tolerance
• Familiarity with GitHub Actions for CI/CD
• Experience with managing and processing data
• Oral communication and interpersonal skills
• Highly organized with strong time-management and prioritization skills
• Flexibility and ability to multitask and pivot between priorities
• Excellent command of the Greek and English language

 Will be highly appreciated:

• Experience in fintech or payments
• Familiarity with microservices architecture
• Knowledge of test automation frameworks (JUnit, Mockito, etc.)
• Broader CI/CD experience beyond GitHub Actions
• Exposure to advanced AWS services (e.g., Lambda, ECS, Kinesis)