Job Summary: A professional is needed to modernize a legacy system, migrate business logic to WebAPI, develop REST APIs, and ensure quality through automated testing. Key Highlights: 1. Modernization and migration to web architecture (ASP.NET Core WebAPI + React) 2. Develop and structure organized, scalable REST APIs 3. Ensure quality through automated testing We are a technology company specializing in transportation management solutions for freight road transport (TMS/WMS/Finance), with a mature desktop-based C# multi-layer architecture deployed in the market for years. We are currently undergoing modernization and migration to a web architecture (ASP.NET Core WebAPI + React + Vite + Tailwind), preserving established business rules and ensuring quality through automated testing. **Responsibilities:** * Migrate existing business logic (C# layered architecture) to WebAPI * Develop and structure organized, scalable REST APIs * Maintain clear separation between Controller, Service, Domain, and Data layers * Ensure integrity of existing business rules during migration * Implement mandatory automated tests prior to deployment * Integrate backend with React frontend (Vite + Tailwind) * Participate in defining and evolving the project’s technical architecture The professional will directly handle the modernization of the legacy system to a web environment. Required Qualifications **Backend** * Advanced C# * ASP.NET Core WebAPI * SQL Server (T-SQL, performance tuning, indexes, transactions) * Experience with layered architecture or Clean Architecture * Experience with legacy system migration or modernization * API versioning * Git (workflow with Pull Requests) **Automated Testing (Mandatory)** * xUnit or NUnit * Unit testing of business logic * Use of mocks (Moq or similar) * API integration testing * Mindset of minimum test coverage before production **Frontend** * React (Hooks) * Consumption of REST APIs * Vite * Tailwind CSS * Component organization Interested candidates should send their application to email: **nivel2@amantran.com.br** with code DEV1 Employment Type: Full-time CLT Compensation: R$4.957,92 – R$9.413,80 per month Benefits: * Health insurance * Dental insurance * Life insurance * Meal allowance * Transportation allowance Work Location: On-site