Juvinal A.

I build reliable web applications, APIs, and AI-powered mobile products. My core stack is C#, ASP.NET Core, Blazor, and SQL Server, with hands-on experience taking features from requirements through testing and deployment. My Upwork track record includes $60K+ earned, 5,800+ hours, and 100% Job Success. Clients have trusted me with long-term development work, subscription integrations, and business applications. AI APPLICATION ENGINEERING I created YellowHat, a privacy-focused online safety app that uses on-device AI to analyze selected Android notifications for possible bullying, grooming, threats, and scams. YellowHat Kids is published on Google Play. The app processes notification content locally and helps parents review potential concerns. This work combines applied AI with mobile development, notification processing, device pairing, configurable alerts, and backend integration. I bring that same product-focused approach to client projects: turning an AI capability into a useful application with clear controls and dependable workflows. HOW I CAN HELP - Build and maintain C# / ASP.NET Core web applications and REST APIs - Develop Blazor interfaces and business dashboards - Integrate AI capabilities into web and mobile applications - Build subscription and payment workflows, including Stripe integrations - Design SQL databases and connect third-party services - Troubleshoot existing applications and improve reliability - Implement unit tests and CI/CD pipelines with Azure DevOps I focus on maintainable code, clear communication, and practical technical decisions. Whether you need a new product, an AI feature, or support for an existing .NET application, share your goals and I can help define the next steps.