Senior Backend Engineer

EFA GROUP comprises companies in Aerospace, Security, Defense, and Industrial Cooperation with a solid international presence. EFA GROUP currently employs more than 400 people, the majority of whom are engineers and scientists. Headquartered in Greece, the Group maintains a strong international presence across Europe (Cyprus, Belgium, Switzerland, Estonia, and Germany), Asia (Singapore, Indonesia, and South Korea), the Middle East (UAE), and the United States, serving customers in 34 countries worldwide.

The GROUP includes EFA VENTURES (Supply Chain Management and integrated services), AEROSPACE VENTURES (Industrial Participation and related services), SCYTALYS (Systems Integration and Software), ES SYSTEMS (MEMs & IoT Integration), EPICOS (Global Defense B2B Information Platform), UCANDRONE (Unmanned Systems), AETHER AERONAUTICS (Target Drones), STHENOS AI (Intelligence Solutions), THYREOS CYBER (cyber security), SUPERIOR AIR (aviation services and specialized aerial missions), SSMART (defense hardware - software production and services).

SSMART is a Greek high-technology company specializing in Radar systems, Combat Management Systems (CMS), Command & Control (C2) solutions, software development, and systems integration for naval and mission-critical applications. Since July 2026, SSMART has been part of EFA GROUP, strengthening the Group’s capabilities in advanced defense technologies.

The Role

SCYTALYS is looking for an experienced and motivated Senior Software Engineer who will be at the heart of designing and building our systems. You will translate requirements into well-architected, maintainable software and play a key role in shaping the technical direction of the products you work on.

Key Responsibilities

• Design and develop high-quality software solutions using Java and Spring Boot
• Analyze technical requirements and translate them into scalable software designs
• Architect and implement core application features and backend services
• Integrate internal and third-party systems to enhance functionality and performance
• Optimize applications for performance, reliability, and maintainability
• Collaborate with engineers, architects, and stakeholders throughout the development lifecycle
• Contribute to technical decisions and propose solutions to engineering challenges

Requirements

• 5+ years of professional software development experience
• BSc degree in Computer Science, Electrical/Electronics Engineering, or a related field
• Strong experience with Java (Java 8/11) and Spring Boot
• Ability to analyze requirements and design scalable software solutions
• Good understanding of Linux/Windows environments and networking concepts
• Experience with relational and NoSQL databases, including JPA/Hibernate or Spring Data
• Experience in application debugging, performance optimization, and troubleshooting
• Strong communication and teamwork skills

Nice to Have

• Experience with Angular, React, or Vue
• Knowledge of microservices architecture, RESTful/gRPC APIs, and reactive programming
• Experience with C/C++, Kafka, RabbitMQ, or ActiveMQ
• Familiarity with Maven/Gradle, Git, Docker, and Kubernetes
• Experience with database tuning, migrations, caching technologies (e.g. Redis), and geospatial databases
• Exposure to Defence, Security, or Command & Control systems
• Knowledge of Tactical Data Links, NATO standards, GIS, or OGC technologies