Senior Java Backend Developer

Senior Java Backend Developer Location: Istanbul / Gebze (On-site) Employment Type: Full-time About the Role We are looking for a Senior Java Backend Developer to join our engineering team in an on-site working model at our Istanbul / Gebze office. The role involves hands-on backend development, architectural ownership, and effective use of AI-assisted development tools to improve code quality and engineering efficiency. Responsibilities Design, develop, and maintain scalable backend services using Java and Spring Boot Own the design and evolution of REST and/or GraphQL APIs Take responsibility for backend architecture and long-term technical decisions Design and optimize database schemas and complex SQL queries Implement and maintain event-driven and message-based systems (Kafka, MQTT, RabbitMQ) Leverage AI tools (e.g. code assistants, AI-powered IDE features) to improve development speed and quality Conduct code reviews and enforce clean code and best practices Identify, prioritize, and reduce technical debt Improve system performance, stability, and reliability Collaborate closely with on-site engineers and stakeholders Requirements 4+ years of professional experience in Java backend development Strong expertise in Java (17+) and the Spring Boot ecosystem Proven experience building and maintaining production-grade backend systems Advanced knowledge of RESTful API design and backend architecture Strong SQL skills and experience with relational databases Deep understanding of JPA / Hibernate , including performance tuning Solid knowledge of concurrency, multithreading, and JVM performance Experience with Git and CI/CD pipelines Hands-on experience using AI-assisted development tools (e.g. ChatGPT, GitHub Copilot, Cursor, IDE AI features) Strong understanding of clean code, SOLID principles, and design patterns Nice to Have Experience integrating AI or ML-based services into backend systems Experience with Kafka, MQTT, or real-time data processing Docker and container-based deployment experience Familiarity with cloud platforms (GCP, AWS, etc.) Microservices and distributed systems experience Observability tools (Prometheus, Grafana, ELK stack) Experience with IoT or high-throughput systems What We Offer On-site collaboration with a highly technical engineering team Direct impact on architectural and technical decisions Long-term, stable projects with real production usage Engineering-driven culture that encourages effective AI usage How to Apply Please submit your CV and, if available, links to GitHub, technical blogs, or relevant projects.