Songhwa Chae

Sahmyook University SU-CareShop

Volunteer Work Matching System for Univ Students
- Java/Spring Boot/Javascript/jQuery/MySQL
- Designed and Implemented APIs.
- Front-end programming.
- Created SQL statements.
- Testing.

Korea SDA English Institution Online English Class

Review lessons online.
- Java/Spring Boot/Javascript/jQuery/XML/MySQL
- Converted Flash programs to modern web application.
- Designed and Implemented APIs.
- Refactoring.
- Front-end programming.
- Testing.

Kookmin University Mobile Application

One-step application with messenger, QR Attendance, scheduler, class bulletin board, etc.Worked especially on scheduler, class bulletin board, automatic database table creation.
- Java/Spring Boot/Javascript/jQuery/Angular JS/MySQL
- Designed and Implemented APIs.
- Built Spring batch engines.
- Front-end programming.
- Created SQL statements.
- Testing.

Sahmyook University SU-Pay

On-campus mobile payment system
- Java/Spring Boot/Javascript/AngularJS/MySQL

Sahmyook University Suwings Maintenance

Intranet System Maintenance and Improvement

VITCON IoT Device Data Visualization

Parse log files and save data into database. Visualize.

Volunteer Matching Web Platform

Developed a web-based platform for matching university students with volunteer opportunities.

Tech Stack

Java, Spring Boot, MySQL, JavaScript, jQuery

Responsibilities

• Designed and implemented RESTful APIs for user and matching functionalities
• Developed frontend features for user interaction and data display
• Designed database schema and wrote optimized SQL queries

Key Contributions

• Built end-to-end matching workflow between users and volunteer programs
• Structured API and database interaction for efficient data handling
• Improved data consistency through input validation and backend logic

Impact

• Enabled efficient volunteer matching process for university users
• Improved usability and data reliability of the platform

Legacy System Modernization (Flash to Web Application)

Migrated a legacy Flash-based learning system into a modern web application without access to the original source code by reverse-engineering client-server communication.

Tech Stack

Java, Spring Boot, Tibero, AngularJS, XML, Wireshark

Responsibilities

• Reverse-engineered existing Flash application behavior by analyzing network traffic
• Captured and inspected request/response packets using Wireshark to identify APIs and data structures
• Reconstructed backend communication logic and redesigned it into RESTful APIs
• Converted Flash-based functionalities into web-based features using JavaScript and jQuery
• Refactored and restructured system architecture for improved maintainability

Key Contributions

• Successfully rebuilt system functionality without original source code by analyzing network-level communication
• Identified hidden API endpoints, request patterns, and data formats through packet inspection
• Reimplemented core features with a modern, scalable web architecture
• Reduced technical debt by replacing tightly coupled legacy logic with modular backend services

Impact

• Eliminated dependency on deprecated Flash technology
• Enabled continued service operation despite lack of original source code
• Improved system maintainability, scalability, and extensibility
• Enhanced accessibility by transitioning to a browser-based platform compatible with modern environments

Campus Mobile Payment System (SU-Pay)

Developed a campus-wide mobile payment system (SU-Pay) that allows students to use scholarship-based points earned from extracurricular activities as digital currency at on-campus stores. Integrated into the university’s official mobile app, this system was the first of its kind among universities in Korea.

Tech Stack

Java, Spring Boot, MySQL, AngularJS

Responsibilities

• Reverse-engineered existing Flash application behavior by analyzing network traffic
• Captured and inspected request/response packets using Wireshark to identify APIs and data structures
• Reconstructed backend communication logic and redesigned it into RESTful APIs
• Converted Flash-based functionalities into web-based features using JavaScript and jQuery
• Refactored and restructured system architecture for improved maintainability

Key Contributions

• Successfully rebuilt system functionality without original source code by analyzing network-level communication
• Identified hidden API endpoints, request patterns, and data formats through packet inspection
• Reimplemented core features with a modern, scalable web architecture
• Reduced technical debt by replacing tightly coupled legacy logic with modular backend services

Impact

• Eliminated dependency on deprecated Flash technology
• Enabled continued service operation despite lack of original source code
• Improved system maintainability, scalability, and extensibility
• Enhanced accessibility by transitioning to a browser-based platform compatible with modern environments