Monika K.

Have a WPF or .NET desktop application your business runs on every day? For 9+ years and 14,400+ hours, I've been the main developer of one client's business-critical WPF/XAML application. I keep apps like that stable, add the features your team needs, and modernize them step by step without stopping daily work. Top Rated · 100% Job Success · $100K+ earned · 14,600+ hours on Upwork · Microsoft Certified: .NET Developer WHAT I DO • WPF, XAML and MVVM desktop apps: new apps, new features, bug fixes, custom controls and styling, including DevExpress • Taking over existing desktop software: I learn your codebase, fix what's fragile and keep it running • Payment and system integrations: CardConnect payment gateway, POS, Microsoft Dynamics 365, REST APIs and third-party services • ASP.NET Core Web APIs and Blazor, so your desktop app can share data with web and mobile apps • AI features in existing .NET software with OpenAI and Azure OpenAI, where they save real time • SQL Server, PostgreSQL, Entity Framework and Dapper, plus Azure and Azure DevOps CI/CD MIGRATION & MODERNIZATION • .NET Framework to .NET 8 for WPF and WinForms apps, in stages • WinForms to WPF with MVVM • Desktop features moved to the web with ASP.NET Core or Blazor when needed • Older UIs refreshed with modern XAML styling and DevExpress controls PROJECT EXPERIENCE • WPF/XAML business application, 2017 to present: 9+ years and 14,400+ hours of development, new features and maintenance for one client • CardConnect payment gateway integration (current project) • Point-of-sale (POS) system enhancements in C# and .NET • .NET backend with Azure and Microsoft Dynamics 365 integration • WPF ticket booking and product ordering apps • Sitecore CMS website with ASP.NET, Angular and Tailwind CSS, including AI features HOW I WORK I agree a clear scope and milestones before I start, send regular progress updates, and test every delivery myself (5+ years of manual QA experience). I use AI-assisted tools to speed up routine work and review every change before it ships. Flexible hours with US, UK, EU and Australian overlap, Zoom calls when needed, and NDA on request. STACK C#, .NET 8, .NET Framework, WPF, XAML, MVVM, WinForms, DevExpress, ASP.NET Core, Blazor, SQL Server, Entity Framework, Dapper, Azure, Azure DevOps, Dynamics 365, OpenAI Send me a short note about your application and what needs to change, and I'll suggest a practical first step. Hired as: C# Developer, .NET Developer, WPF Developer, XAML Developer, MVVM, Windows Desktop Application Developer, WinForms Developer, DevExpress, Legacy .NET Modernization, .NET Framework to .NET 8 Migration, Payment Gateway Integration, CardConnect, POS Software Developer, Dynamics 365 Integration, ASP.NET Core.