Korolous Y.

Senior Java Software Engineer | Spring Boot | Microservices | Cloud & DevOps I am a Senior Java Software Engineer with over 4 years of experience building secure, scalable, and high-performance backend systems for telecom, enterprise, and SaaS applications. My expertise spans Java, Spring Boot, RESTful APIs, Microservices, and reactive programming (Spring WebFlux), along with hands-on experience in cloud services, containerization, and CI/CD automation. I help businesses transform ideas into robust, production-ready solutions by focusing on clean architecture, performance optimization, and long-term maintainability. My work consistently delivers faster response times, reduced operational costs, and improved system reliability. What I Do Best - Backend Development: Scalable REST & reactive services using Java, Spring Boot, Spring Data, Spring Security, Hibernate, and WebFlux. - Cloud & Serverless Solutions: AWS DynamoDB, Google Cloud APIs, Microsoft Vision API. - Microservices Architecture: Secure, containerized deployments with Docker, Kubernetes, and OpenShift. - Database Management: Oracle, PostgreSQL, MySQL, Redis, MongoDB, Firebase. - Messaging & Event-Driven Systems: Apache Kafka, RabbitMQ for distributed communication. - API Documentation & Integration: Swagger/OpenAPI, third-party API integration. - UI Integration: Angular, React plugins for enhanced user experience. Professional Highlights - Etisalat Egypt (Systems Limited) – Developed high-throughput, non-blocking backend services using Spring WebFlux, integrated AWS DynamoDB for ultra-fast NoSQL access, and built event-driven workflows with AWS Lambda, significantly reducing operational costs. - Vodafone Egypt (Systems Limited) – Modernized legacy systems (Apache Struts, JSP) into secure Spring Boot microservices, managed Oracle DB with 1M+ records, deployed containerized services on OpenShift, and configured SSL/TLS for secure JBoss deployments. - IST Networks – Built scalable REST APIs, integrated MySQL & third-party APIs, deployed services on Tomcat, linked Genesys Cloud & Cognigy AI with backend systems, and created React plugins to improve conversational AI UX. - Android Development – Delivered mobile apps using Java, Kotlin, Firebase, Google APIs, and taught Android development (Java, SQLite, Firebase) to aspiring developers. Notable Projects - Jobify: Job listing web service with Spring Boot, Spring Data JPA, and JWT security. - Pharmacy Management System: Spring Boot + MySQL system with Swagger documentation. - Bluetooth Smart Car Control App: Android app to control an embedded smart car via Bluetooth using Java/Kotlin. Why Work With Me ✅ Client-Focused: I understand business needs and translate them into technical solutions. ✅ Scalable & Maintainable Code: Clean architecture, SOLID principles, and efficient algorithms. ✅ End-to-End Expertise: From backend architecture to cloud deployment and monitoring. ✅ Problem-Solver: Skilled at debugging complex systems and improving performance. ✅ Proven Track Record: Delivered projects for top telecom companies with millions of active users. Tech Stack - Languages: Java, Kotlin, SQL - Frameworks: Spring Boot, Spring WebFlux, Hibernate, Angular, React plugins - Cloud: AWS, Google Cloud, Firebase - Databases: Oracle, MySQL, PostgreSQL, Redis, MongoDB, DynamoDB - Messaging: Kafka, RabbitMQ - Tools: Docker, Kubernetes, Jenkins, OpenShift, Swagger, Postman, Jira, Confluence - Version Control: Git, GitHub, GitLab, Bitbucket, Gitea