The purpose of async programming in modern applications is to enhance application performance and responsiveness by allowing non-blocking execution of tasks. This programming paradigm enables developers to write code that can handle multiple operations simultaneously, particularly I/O-bound tasks, without freezing the user interface or compromising overall functionality. Asynchronous programming reduces wait times during data retrieval or processing, leading to smoother user experiences. By leveraging async patterns such as callbacks, promises, or async/await, developers can create efficient applications that provide real-time interactions and improved resource utilization.