Designed and implemented core features of an online education platform built with Spring Boot; planning and implementation of key Android-based application functions; designed and documented GraphQL APIs, leading collaboration with the frontend/client team; architected ORM structures using Hibernate and JPA, optimizing complex queries for better performance; improved CI/CD pipelines and stabilized deployment processes through GitHub Flow; led onboarding for new developers and conducted regular code reviews; refactored and maintained features based on user feedback to enhance system reliability.

Java Developer at Netstream Co., Ltd (South Korea)

March 1, 2025 - April 1, 2025

Led the development of scalable modules for an AI-based online education platform; designed user registration, content management, and recommendation services; improved query performance by 30% through advanced Hibernate tuning; built REST APIs and collaborated with frontend teams for integration; maintained CI/CD pipelines and contributed to DevOps processes; mentored junior developers and conducted code reviews.

Java Developer at Morago Ltd at Seoul (South Korea)

April 1, 2023 - April 1, 2024

Developed microservices for real-time translation and order processing systems; implemented authentication using JWT and OAuth2 across services; proposed architecture refactoring that improved stability and maintainability; managed Docker-based environments and integrated Jenkins pipelines; worked closely with product managers and designers to define APIs.

Java Developer at Sberbank Ltd (Russia)

September 1, 2021 - September 1, 2022

Participated in the development of internal banking systems; wrote backend logic under supervision, fixed bugs, and applied code standards; configured Tomcat and MySQL on Windows servers; gained experience with Spring Boot and REST API; supported QA with test cases and collaborated on bug tracking.