Hi, I'm OhJ.
Passionate Full-stack Developer with expertise in Next.js, Nest.js, and AWS — building scalable, modern, and user-centric web applications.
Projects Showcase
Here are some of my key projects demonstrating problem-solving and technical skills.
BusinessPlus CRM
Redesigned main site for B2B IT consulting firm BusinessPlus
Hanleeon Patent Consulting
Refreshed Cafe24-based website for a patent law firm
Inno3Dental Chat
Real-time group chat feature within the partner network platform
Inno3Dental Dashboard
Admin dashboard with report lists, storage metrics, and charts
Report Management
Report list and detail view with date/keyword filters
Account & Profile
Account settings (General, Security, Scanner) and user profile screens
Kiosk Payment Integration System
Development and deployment of a kiosk payment integration system
My Career Journey
My career has grown through challenges. Here are the roles and skills I've built along the way.
Queen's Smile
Contract Developer2025.07 ~ 2025.07 · 1 weeks
- Implemented QR code and barcode scanner integration functionality
- Handled RS232 serial communication using SerialPort and managed data receive events
- Developed prefix-based logic for data length recognition and byte string parsing
- Applied regular expression filters and validation for scanned data
- Integrated scanner input with React-based Kiosk UI via asynchronous communication
- Processed scanned data through HTTP requests and reflected responses in the UI
- Implemented fallback alerts and error handling for disconnected or malfunctioning devices
📦 Tech Stack: C#, WinForms, SerialPort, Regex, JavaScript, React, HTTP
Queen's Smile
Contractor2025.06 ~ 2025.06 · 2 weeks
- Developed kiosk payment integration system and set up production environment
- Built HTTP plugin for tPayDaemon in C#/.NET
- Optimized HttpClient settings, implemented SSL and JSON binding
- Stabilized payment requests on /Auth and /Cancel endpoints
- Embedded Chromium (CefSharp.WinForms) and bound JS↔C#
- Configured JavascriptObjectRepository and handled Chrome API communication
- Integrated EMV card terminal via serial port with ACK logic
- Implemented auto POS data filling, debugging logs, and fallback handling
📦 Tech Stack: C#, .NET Framework, CefSharp, HttpClient, JSON, WinForms, SerialPort, Windows Registry
Inno3D
Platform Team Senior Researcher2022.04 ~ 2025.05 · 3 years 2 months
- Designed and developed real-time ordering, 3D file viewer(three.JS), login persistence, and partner network platform
- Deployed high-availability platform on AWS EC2, RDS, and load balancers
- Implemented JWT login with OTP, Nest.js Guards for RDS protection
- Used Redis for session sharing and restart-persistent sessions, RDS replication for backend scaling
- Built 1:N real-time group chat with WebSocket + Bull Queue for high traffic
- Automated AWS IAM and Git environment setup
- Improved bug resolution efficiency by 40% with Jest-based testing
📦 Tech Stack: AWS, Nest.js, React, Redis, WebSocket, Bull Queue, PostgreSQL, Jest
HappyMade
Dev Team Lead2021.08 ~ 2022.01 · 6 months
- Developed admin and user pages for in-house exchange service in PHP
- Integrated MySQL-based data and fixed bugs
📦 Tech Stack: PHP, MySQL, HTML, CSS, JavaScript
Han Communication
Developer2021.05 ~ 2021.08 · 4 months
- Maintained client websites and created storyboards
- Developed full-stack client sites on Cafe24
- https://hanleeon02.cafe24.com/main/
📦 Tech Stack: HTML, CSS, JavaScript
BeFle (BusinessPlus)
Corporate Researcher2020.09 ~ 2020.11 · 3 months
- Redeveloped company website and built admin panel
- Implemented backend in PHP/MariaDB and frontend in JS/HTML/CSS3
- Created notice, gallery, and video boards
- Handled web publishing
- http://www.businessplus.co.kr/
📦 Tech Stack: PHP, MariaDB, HTML, CSS, JavaScript
Hanil Networks
Business Support Staff2017.01 ~ 2018.07 · 1 year 7 months
- Managed department costs, budgets, marketing, and planning
- Supported general affairs, accounting, document management, procurement, and ERP operations
📦 Tech Stack: ERP, MS Excel, Office
Let's Connect
Feel free to reach out anytime via email, or check out my work on LinkedIn and GitHub.
