Hiring an Application Infrastructure Design developer is crucial for creating robust, scalable, and efficient software applications. They are experts in designing the underlying structure that supports application's functionalities, ensuring optimal performance and security. They understand the complexities of various technologies, servers, databases and can effectively integrate them. Additionally, they can help in disaster recovery planning and contribute towards maintaining business continuity. Their expertise can lead to cost savings by optimizing resources and reducing downtime. Thus, their role is pivotal in successfully managing and enhancing your application's infrastructure.