An IIS developer primarily works with Microsoft’s Internet Information Services (IIS) version ., a web server application and set of feature extension modules. The developer's duties include designing, developing, and maintaining websites, web applications, and web services on the IIS platform. They are responsible for configuring IIS settings, troubleshooting issues, and ensuring website performance and security. They also ensure smooth deployment of web applications and often collaborate with other developers and IT professionals to integrate IIS with other software. Their role often requires knowledge of ASP.NET, SQL Server, and other Microsoft technologies.