A UX Developer can also be described as a User Experience Developer. Another way of understanding their role is imagining them as a type of 'front end developer', or an 'interaction designer'. Essentially, it's a hybrid set of skills between that of a coder, and that of a designer.
Is a UX designer a web developer?
They're each working on two separate—but related—sides of the same product. Although both skillsets are required to build a website that meets the needs of the people hoping to use it, in a practical sense a web developer and a UX designer do not work side by side, but rather one after the other.
Is UX part of development?
Being part of a scrum team, developers, testers and UX designers work together. In this approach, it is important to keep UX work ahead of development so that things do not get delayed in a sprint. This makes the role of UX designer very critical.