Not all web developers are created equal. Web development is a very technical job that requires a lot of skills and it could be done remotely. A San Diego web development company can develop code for another company in the east cost. Writing code now days could be done in so many different ways.
Some developer writes spaghetti code. This is a code where your HTML mixed with your database query and mixed with your scripting language. We call that spaghetti code.
The right way of writing code forces you to separate your code by creating some kind of frame work. One of the most popular frame works is the MVC frame work. This is stand for module, view, control framework. HTML is no longer the way the write code, the use of CSS and DHTML is becoming more popular with the rise of search engine marketing and the way your load time might effect the conversion rate of the users that are visiting your site.
A good web development company will use some form of framework, CSS, DHTML, and AJAX and follow the W3C standers.