Senior Fullstack .NET Developer

Location: remote Employment Type: B2B Salary: 110-145 PLN/h We are looking for an experienced Senior Fullstack .NET Developer for a client from Ireland. The platform being created supports comprehensive management of processes related to the licensing and regulation of the taxi market, covering, among others, the registration of taxi corporations, management of driver licenses, and administrative processes carried out by local government and regulatory bodies. Responsibilities: * Design, develop, and maintain solutions based on .NET 8/9, including APIs, backend services, asynchronous processes, and legacy applications. * Lead architectural discussions and create and maintain technical documentation (ADR – Architecture Decision Records). * Analyze business requirements and translate them into scalable, secure, and high-quality technical solutions. * Mentor developers at the Regular and Junior level through code reviews, pair programming, and technical sessions. * Ensure code quality, programming standards, and the development of automated tests. * Develop and optimize CI/CD processes in Azure DevOps or GitHub Actions. * Implement and develop monitoring, logging, and observability mechanisms. * Support the use of AI tools in the software development process (GitHub Copilot, Azure OpenAI). * Collaborate with Product Owners, Architects, and Scrum teams. * Participate in the selection and implementation of new technologies consistent with the Microsoft/Azure strategy. * Support production environments, analyze incidents, and implement corrective actions. * Perform frontend tasks in React / Next.js technologies. Expectations: * Very good knowledge of .NET 8/9, C# 12+, ASP.NET Core. * Experience in creating Minimal APIs, REST APIs, and SignalR. * Knowledge of legacy technologies: .NET Framework, ASP.NET Web Forms, and MVC. * Practical knowledge of EF Core 8, SQL Server, and Azure SQL. * Experience in TypeScript. * Practical knowledge of React 18+. * Knowledge of Clean Architecture. * Experience with CQRS and MediatR. * Experience in building and maintaining CI/CD pipelines in Azure DevOps. * Minimum B2 level enabling fluent communication in an international environment. We offer: * Rate up to 145 PLN/h net on a B2B contract * Payment in a convenient form * Short 14-day invoice payment term * Rich package of private medical care services * Access to the MyBenefit cafeteria platform (allowing you to order Multisport cards, prepaid cards for Ikea, Zalando, Notino, and many others)