Strong coding skills are essential. Mastering programming languages such as HTML and CSS is just a start. Technology changes fast, so a willingness to always be learning new coding techniques is important.
Testing and debugging code requires patience and analytical skills to understand what went wrong and how to fix it.
Successful websites have to attract and keep users, as well as be visible to search engines. Web developers have to be creative in user experience, search engine optimization, and other factors.
While many web designers work alone, most work for an organization. Understanding the needs of the sales department, for example, is crucial in creating a successful website. Collaborating with user experience or content creation experts is also a necessary skill.