Hiring a Fluent NHibernate developer is beneficial as they can provide robust data access solutions for your .NET applications. Their expertise helps in simplifying database operations, reducing boilerplate code and enhancing maintainability. They can map your object-oriented code to the database, enabling efficient data manipulation. Their skills can also help in implementing complex mapping scenarios, ensuring the agility and flexibility of your projects. Overall, a Fluent NHibernate developer can contribute to quicker, reliable, and scalable application development.