C# / .NET Developer

Description

Job Summary: This project seeks a developer to maintain and evolve backend solutions built with ASP.NET Core and Windows desktop applications (WinForms), using modern .NET and C#. Key Highlights: 1. Maintenance and evolution of ASP.NET Core and WinForms solutions 2. Working with modern .NET, C#, Dapper, SQL Server/PostgreSQL 3. Experience with automated testing and HTTP integration About the Project: Maintenance and evolution of solutions with ASP.NET Core backend (Web API) and Windows desktop applications (WinForms), including integrations with external services, mocks for test/environment support, and shared internal libraries. The environment uses modern .NET (net9/net10\) and recent C\# features. Responsibilities: * Evolve and sustain ASP.NET Core APIs (Controllers, middlewares, DI, configuration, pipeline). * Develop HTTP integrations with partners/external services (JSON contracts, error handling, resilience). * Maintain and evolve WinForms modules (UI forms, event handling, performance, stability). * Implement data access using Dapper/Dapper.Contrib with SQL Server and PostgreSQL. * Ensure observability and diagnostics (logging with Serilog, NLog, troubleshooting and fixes). * Write and maintain automated tests and support quality/coverage. * Participate in code reviews, refactorings, and technical decisions (continuous improvement). Requirements: Mandatory Requirements: * Solid knowledge and practical application of design patterns and coding best practices: DRY, SOLID, GRASP * Experience with agile frameworks (Scrum, story points, planning, retrospectives). * Solid experience with C\# and modern .NET. * Experience with ASP.NET Core Web API (Swagger/OpenAPI, health checks, authentication/authorization). * Experience with Dapper and SQL Server and/or PostgreSQL databases. * Experience with HTTP integration and JSON serialization (Newtonsoft.Json). * Experience with logging and troubleshooting (Serilog, NLog). * Experience with automated testing: xUnit and mocks with NSubstitute. * Solid knowledge of Git and branching strategies * Extensive experience with collaborative development best practices (PRs, code review, merging). * Experience with pipelines using GitHub Actions. Nice-to-Have (Differentiators): * Familiarity with Python (Virtualenv, Jinja, Django, Flask, Freeze) * Basic knowledge of automation for internal SDK/build routines. * Advanced WinForms and/or DevExpress WinForms. * Resilience with Polly. * Experience with Flurl and/or Refit. * Verify (snapshot tests) and Shouldly. * Familiarity with Fody and/or Roslyn/Source Generators.