A jQuery .+ developer is skilled in a powerful, fast, and concise JavaScript library that simplifies HTML document traversing, event handling, animating, and Ajax interactions. They can create feature-rich, interactive, and responsive websites with optimized performance and user experience. Their knowledge in jQuery .+ ensures they can handle deprecated or removed features, and are updated with latest improvements. They're proficient in dealing with cross-browser compatibility issues, ensuring your website works seamlessly on various browsers. Their expertise can be pivotal to your web development projects, improving your digital presence and customer engagement.