A little sight into the UI developer works:

What is a MVC ?

the model view controller pattern is a pattern based on the names of its main parts, which are as follows.

Model: this is a domain specific representation of the information on which application operates.The model is another name for the domain layer.Domain logic adds meaning to raw data(for calculating if today is the birthday of the user ,or the taxes and shipping charges for the shopping cart).

View : renders the model into a form suitable for interaction ,typically a user interface element.MVC is often seen in web applications where the view is the HTML page and code which gathers dynamic data for the page.

Controller : Processes and responds to events ,typically user actions and invokes changes on the model and perhaps the view.

What are key tasks of a UI developer :

1-Create a web application front end as per design comps and information architecture.

2-Integrate front end application with the application business layer.

3-Follow best practices and standards for accessibility and cross browser comparability.

4-Collect feedback from design and technical staff on website development needs.

5-Stick to established coding standards and groups procedures individually and in teams.

6-Coordinate with interface design architects for meeting standards at code level.

7-Design and build UIs on any server platform in a team environment.

A user Interface developer for short is not someone who knows a bit of HTML .As developers for web we must know about HTTP and siblings ,HTML,css,JavaScript ,j query ,AJAX ,J son and multiple browsers and their differences ,tools and programmes that deal with web communications.As developers you must know about the human cognition ,basic psychology and logic sorting .You should also have good common sense and must know about all technologies offerings in accessibility and usability interaction principles , MVC platform separation ,languages for creating interfaces and generally tool kits ,tools and programmes that deal with interfaces .