An ASP developer is responsible for designing, implementing, and maintaining web applications using ASP.NET ., a server-side web development framework by Microsoft. They use languages like C# or VB.NET to develop dynamic, interactive, and data-driven web applications. Their tasks include creating database-driven web interfaces for data input and retrieval, integrating existing business systems, troubleshooting and debugging applications, and ensuring security and data protection. They also work with other developers, UI designers, and testers to produce high-quality code, and often participate in the entire software development life cycle, including requirements analysis, design, implementation, testing, and deployment.