HUYNH L.Private profile: Upwork shows its earnings only to signed-in members, so we check it every few weeks, not daily. MRR here is a rough estimate (Upwork's six-month earnings ÷ months active). Last read Nov 5, 2026.

If you need a veteran developer to build robust business applications, AI-powered solutions, desktop software, or custom tools that interact with major marketplaces, let's talk. With 25+ years of software engineering experience, my core strength is building reliable business applications backed by high-performance SQL Server databases. I also develop AI solutions using Microsoft Semantic Kernel, OpenAI, and .NET, including AI assistants that use kernel functions to work with real business data. CORE TECHNICAL EXPERTISE: • AI & Semantic Kernel: Building AI assistants with Microsoft Semantic Kernel, OpenAI, kernel functions, automatic function calling, AI-to-SQL data integration, and function invocation logging. • Desktop Applications (Windows & Mac): Expert in Windows Forms, C#, VB.NET, DevExpress, and native macOS development using Objective-C. • Database & Backend: SQL Server, T-SQL, database design, optimization, REST APIs, and server management (Local, AWS, Azure). • Marketplace Integrations & Custom Tools: Developing automation software, inventory/order synchronization tools, and API integrations for Amazon (SP-API), Walmart, Best Buy, and Macy's. • Web, Mobile & Automation: .NET, TypeScript, Angular, REST APIs, Chrome Extensions, and Google Apps Script. BUSINESS DOMAINS: Warehouse & Freight Management, Barcode Technology (1D/2D), ERP/Accounting integrations, Retail & Wholesale, Customer Management, and Financial Systems. HOW I CAN HELP YOU: • Build AI-powered business applications using .NET, Semantic Kernel, OpenAI, and SQL Server. • Build, modernize, or scale custom Windows desktop applications and SQL databases tailored to your workflow. • Develop or troubleshoot automated tools and API integrations connecting your business systems to Amazon, Walmart, Best Buy, and other marketplaces. • Integrate AI into existing business applications and databases using controlled, reliable backend functions. Available for ~30 hours/week. If you need clean, reliable code and deep technical execution—with 25+ years of experience across business applications, databases, APIs, marketplaces, and AI integration—send me a message and let's discuss your project.