• Developed enterprise document management system with full-stack implementation covering frontend and backend architecture.
• Built RESTful APIs for core modules including document upload/versioning, folder management, user authentication, workflow approval, and real-time notifications.
• Designed and optimized MS SQL Server database schema with TypeORM for document metadata, access control, and audit logging.
• Implemented responsive React-based user interfaces with Ant Design for document viewing, OCR text search, and collaborative features.
• Integrated Tesseract.js OCR engine for automatic text extraction from PDF and image files with multi-keyword search capabilities.
• Developed real-time features using Socket.IO including live notifications, document comments, and collaborative editing.
• Created comprehensive role-based access control system with document/folder sharing permissions and approval workflows.
• Optimized file storage with MEGA cloud integration and implemented background processing for large document uploads.

• Developed comprehensive accounting software system with full-stack implementation covering frontend and backend.
• Built RESTful APIs for core accounting modules including document management, accounts payable/receivable, opening balance entry, inventory control, and financial reporting.
• Designed and optimized MS SQL Server database schema with complex stored procedures for accounting operations.
• Implemented responsive React-based user interfaces for data entry, validation, and real-time updates.
• Created interactive Power BI dashboards displaying total revenue, total expenses, and comprehensive financial analytics.
• Developed financial reports including balance sheets, income statements, and custom business intelligence reports.
• Optimized query performance and implemented data integrity controls for accounting transactions.

• Designed and implemented robust backend services supporting AI content generation functionalities
• Developed reusable service modules and maintained comprehensive internal API documentation

• Developed RESTful APIs for authentication, order tracking, and analytics modules.
• Collaborated with frontend engineers to ensure smooth API integration and performance optimization.
• Designed data structures for social media services (YouTube, Facebook, TikTok, etc.) and implemented full order processing workflows.
• Optimized data handling with Redis caching for high-traffic content and MongoDB for persistent storage.
• Integrated payment gateways (Stripe, Cryptomus) and handled secure transaction processing.
• Implemented scheduled cron jobs for system statistics and data synchronization.

• Built GraphQL APIs to efficiently handle complex data relationships such as employee–department–role mappings.
• Designed backend architecture for employee management modules including attendance tracking, leave requests, and approval workflows.
• Implemented role-based access control (RBAC) to manage different permission levels across the system.
• Optimized MongoDB schema and queries to ensure responsive and scalable data operations.
• Participated in code review and sprint planning to maintain code quality and meet release deadlines.
• Coordinated with UI/UX team to translate business requirements into technical solutions.

• Designed and implemented scalable backend services using microservice architecture.
• Decomposed complex features into independent modules for enhanced scalability and maintainability.
• Utilized Redis as message broker for asynchronous inter-service communication.
• Established service orchestration patterns for distributed system coordination.

• Developed comprehensive landing page management system for multiple brands with drag-and-drop admin interface for content management.
• Built RESTful APIs for modular content sections including hero banners, product catalogs, testimonials, news, videos, and SEO optimization.
• Designed MongoDB schema with Mongoose ODM for flexible multi-brand content structure and automated product synchronization.
• Implemented responsive React-based admin panel with real-time preview, form validation, and media upload functionality.
• Integrated with Hong Anh Computer Company's DevOps management system for automated product sync via GraphQL APIs and scheduled jobs.
• Developed version control system for landing page changes with rollback capabilities and change tracking across multiple brands.
• Optimized performance with efficient data fetching, caching strategies, and TypeScript for enhanced code reliability and scalability.

• Developed comprehensive medical sample collection management system with full-stack implementation covering frontend and backend operations.
• Built RESTful APIs for core modules including sample collection orders, staff assignment, clinic/bus station management, supply inventory, and real-time notifications.
• Designed and optimized MongoDB database schema with Mongoose ODM for complex medical workflow operations and role-based access control.
• Implemented responsive React-based user interfaces with TypeScript and Ant Design for data entry, validation, and real-time updates.
• Created interactive dashboards with Recharts displaying collection statistics, staff performance, and comprehensive operational analytics.
• Developed automated notification system using OneSignal push notifications and Nodemailer for email alerts to stakeholders.
• Integrated geocoding APIs for distance calculation and route optimization for sample collection staff.
• Optimized query performance and implemented JWT-based authentication with role-based permissions for secure operations.