Hiring a MEANJS developer is beneficial due to their proficiency in a full-stack JavaScript solution, including MongoDB, Express.js, AngularJS, and Node.js. These tools provide a robust framework for developing efficient, maintainable, and scalable web applications. MEANJS developers can leverage JavaScript both on the server and client side, ensuring seamless data transmission and minimizing compatibility issues. Their skills in this unified language stack can accelerate development time, reduce costs, and improve performance. They can handle everything from database to user interface, making them a versatile asset to your team.