There are many advantages to hiring a Twitter Bootstrap developer. Perhaps the most obvious advantage is that they will be very familiar with the Twitter Bootstrap framework and thus can help you get the most out of it. They will also be able to create custom components and templates that are specifically designed for use with Twitter Bootstrap, meaning that your site will look great and function properly on all devices. In addition, a good Twitter Bootstrap developer will have a strong understanding of responsive design principles, meaning that your site will look great on any screen size.