A .NET (C#) developer designs, develops, modifies, and debugs software applications using C# language on the .NET framework. They utilize .NET libraries and APIs for tasks like data access and network communications. They use ASP.NET for web application development, often working with databases using Entity Framework. Their responsibilities also include troubleshooting and fixing bugs, improving application performance, and integrating systems. They collaborate with other developers, testers, and system architects to create software solutions. They also participate in code reviews and apply best practices for software development. They often work with other technologies such as HTML, CSS, JavaScript, and SQL.