Hiring a Building Web App with Backbone developer is critical for creating efficient, scalable, and interactive web applications. Backbone.js is a lightweight JavaScript library that implements an MVC design pattern, simplifying client-side web app development. It ensures structured code, making it easier to maintain and update. The developer can create single-page applications and multiple-page web apps with complex functionalities. Their expertise can help in building fast, smooth, and optimized applications that offer a superior user experience, enhancing your business's digital presence.