BACKEND- Developed payment service and inventory service. Responsible for handling requests and responses, ensuring reliable and secure transaction processing, and managing inventory data effectively.- Projects involved integrating various payment gateways (MoMo e-wallet , SmartPay, Payoo, Clingme) and refactored payment workflows to align with system.- Languages and technologies: Java (Spring Framework), Databases (SQL: OracleSQL, PostgreSQL - NoSQL: MongoDB, Neo4j), Kafka, Redis Cache, KeycloakFRONTEND- Held a primary role in building the application, including database design, language and base flow for all projects.- Provided support to team members in solution development and code refactoring.- Worked with various hardware devices such as thermal printers, readers (NFC, RFID, etc.) and payment terminals. Catering to various enterprises and offering rich feature sets:POS (Point Of Sale) + Offline mode (starting a shift, placing order without internet and all related such as payments, sales reports, etc.)+ Device connection (handling and managing the connections of devices within the store)+ Integrated payment gateways such as MoMo e-wallet, SmartPay, Payoo, ClingmeKDS (Kitchen Display System):+ Implemented features including real-time order display, managing order priority, updating order status, and integrating with the POS system.- Languages and technologies used: C#, WF Framework, WPF Framework, Firebase, ClickOnce, XAML, ASP .NET MVC, SignalR, Bonjour- Team size: 20 members- Customers: Pho24, Highlands Coffee- Project management tools: Jira, Lark, Trello

- Held a primary role in development of the My Rewards application. Responsibilities included designing and implementing core features, optimizing app performance, and ensuring a smooth user experience. - Actively collaborated with team members to integrate APIs, troubleshoot complex issues, and deliver a robust, scalable solution. - Implemented key features including social login, friend management, task creation and management, rewards collection, and PayPal payment integration. Additionally, supported the submission of the app to the Google Play Store.- Languages and technologies used: Android (Java), RESTful API, Firebase, Google Play Console, Paypal SDK- Team size: 8 members- Project management tools: Trello, Jira