Usman Z.

I help businesses build SaaS products and modernize existing .NET applications. Using C#, ASP.NET Core, React, Next.js, and SQL Server, I develop features, connect business systems, and integrate authentication and payments. With 7+ years of experience, I work on both new products and established applications that need improvements. My Upwork experience includes SaaS development, Auth0 integration with React and ASP.NET MVC, Microsoft ecosystem integrations, and Stripe integration. WHAT I CAN HELP YOU WITH • Full-Stack SaaS Development Build and extend SaaS applications with .NET backends and React or Next.js interfaces. Implement user roles, admin dashboards, subscriptions, and payment workflows. • .NET Modernization & Maintenance Modernize legacy ASP.NET and .NET Framework applications, troubleshoot issues, and add features. Plan upgrades around your existing application and business requirements. • APIs & Business Integrations Develop REST APIs and connect applications with third-party services, Microsoft tools, and existing business systems. • Authentication & Access Control Integrate Auth0, Azure AD, single sign-on, and role-based permissions for applications with different user types and access requirements. • Payments & Subscriptions Integrate Stripe, Stripe Connect, and subscription billing into SaaS products and marketplaces. • SQL Server & Reporting Investigate slow queries, optimize stored procedures, and build reporting features and dashboards. RELEVANT PROJECT EXPERIENCE • Full-stack SaaS product development • Auth0 integration for React and ASP.NET MVC • C# applications involving Azure AD, Dynamics 365, and SharePoint • Stripe website integration • Facility management software • ASP.NET MVC and Angular project setup CORE TECHNOLOGIES Backend: C#, ASP.NET Core, .NET Framework, ASP.NET MVC, Entity Framework, REST APIs Frontend: React, Next.js, TypeScript, JavaScript Database: Microsoft SQL Server, SQL Integrations & Cloud: Auth0, Azure AD, Stripe, Microsoft Azure, AWS Lambda Whether you need a new SaaS application, improvements to an existing .NET system, or a specific integration, send me a brief description of your project, current technology stack, and priorities. We can define the scope and a practical first milestone.