
The designer should take care things like website load, so the images and videos on it should be as small as possible when the file size is considered - visitors don't like to wait a few minutes just for website just to be loading and showing them the content. The website loading is just a part of SEO, there are other things to consider when the search engine optimization for a website is done. Adding some structure for the website and creating more and more backlinks are just two of them and the end result only helps you: the website has more traffic. If you want to do it yourself you need to learn the rules or you just can call someone for help.