Hiring a Java Ant developer is beneficial for managing build processes in Java applications. They possess expertise in the Apache Ant tool, which offers flexibility and control over the build process. They can automate tasks such as compilation, documentation, and packaging of code, thereby enhancing productivity and efficiency. Their skills can help in troubleshooting build errors, ensuring a smooth and continuous development process. Moreover, their understanding of Java adds to their ability to create robust, scalable, and maintainable applications, making them a valuable asset to any development team.