.NET Core Developer Needed for E-Commerce Authentication, Authorization & API Refactoring

We have an existing set of basic e-commerce APIs built with ASP.NET Core. The core APIs are already functional, and we are planning to deploy the application to Microsoft Azure. We are looking for an experienced .NET developer to improve the existing backend by implementing customer onboarding and authentication, API authorization, and standardizing the overall API structure. Scope of Work Customer Onboarding & Authentication Implement a customer onboarding workflow where users can: * Sign up manually using email and password * Sign in using email and password * Sign up/sign in using Google * Securely authenticate users * Protect relevant APIs using authentication and authorization API Authorization * Implement authorization for protected API endpoints * Ensure only authenticated users can access customer-specific functionality * Add role-based authorization where required API Refactoring Review and refactor the existing APIs to improve consistency and maintainability, including: * Global exception handling * Application and error logging * Consistent API response structure * Correct and consistent HTTP status codes * Request validation where required * Clean configuration of the ASP.NET Core middleware pipeline Documentation * Document the authentication and authorization flow * Document middleware and API changes * Provide basic API documentation for the implemented functionality * Add/update Swagger/OpenAPI documentation where appropriate Current Stack * ASP.NET Core / .NET * C# * REST APIs * Entity Framework Core * SQL Server * Microsoft Azure The basic e-commerce APIs are already implemented. The goal of this project is to build a proper authentication and onboarding layer around them, improve API reliability and consistency, and prepare the backend for deployment on Azure. We are looking for someone who has strong experience with ASP.NET Core APIs, authentication/authorization, middleware, API design, and preferably Azure deployment. Please briefly share similar experience with ASP.NET Core authentication, Google sign-in, API authorization, or backend refactoring.