Senior Software Engineer

Summary

Join OKTO as a Senior Software Engineer and take a key leadership role in architecting, designing, and developing our next-generation payment platform. You will leverage your deep expertise in distributed systems, Java-based microservices, and high-volume transaction processing to ensure the platform's scalability, security, and reliability. Collaborate closely with product, infrastructure, and security teams. This position offers significant career growth and the opportunity to make a direct impact in a rapidly expanding international company. We offer a competitive remuneration package and a friendly, motivating, and challenging work environment. Enjoy flexible work-from-home options and continuous training opportunities.

Requirements

• Hold a Bachelor’s or Master’s degree in Computer Engineering or a related field
• Have proven experience (7+ years) in backend software development, with at least 3 years leading teams and architecting payment systems
• Possess a strong understanding of payment flows, settlement, reconciliation, and fraud detection mechanisms
• Have deep knowledge of Java 11+, Spring Boot
• Have strong experience with AWS cloud services, including IAM, EC2, S3, Lambda, RDS, DynamoDB, and API Gateway
• Have hands-on experience with transaction management, database tuning (PostgreSQL, MySQL, or NoSQL stores), and high-availability strategies
• Have extensive experience with Event-Driven Software Design Patterns and complex systems architecture
• Possess expertise in microservices architecture, specifically with Java 8+, Spring Boot, Spring Cloud (Netflix OSS), OAuth2 Security, and JPA ORM
• Possess expertise in designing secure RESTful APIs and working with OAuth2, JWT, and SSO mechanisms
• Have advanced proficiency in Git for source control and versioning
• Have strong technical writing skills, with the ability to produce clear and concise technical requirements, design documents, and specifications
• Have a proven ability to communicate complex technical concepts effectively in both Greek and English

Responsibilities

• Lead the design and architecture of complex distributed systems that handle real-time financial transactions at scale
• Spearhead the integration of payment gateways, banks, card networks, and alternative payment methods
• Take a lead role in our transition to a microservices-based architecture for payments
• Create and maintain high-quality, optimized code with robust unit tests and appropriate test coverage
• Provide technical leadership, mentoring junior developers, and guiding the team in best practices and efficient coding techniques
• Collaborate with cross-functional teams to deliver highly scalable, performant solutions
• Drive continuous improvement initiatives, identifying bottlenecks, and optimizing the software development lifecycle
• Collaborate with DevOps to optimize CI/CD pipelines, and monitoring strategies for production systems

Benefits

• Competitive remuneration package tailored to your experience
• Opportunity to work in a fast-paced, international company with a global presence
• A friendly, motivating, and challenging environment where you can thrive and continue developing your skills
• Continuous training for all your learning and development needs
• Career advancement opportunities, with structured feedback and performance reviews
• Flexible work-from-home options to ensure a healthy work-life balance