[drw85]

One very important skill as a developer, doesn't matter if Frontend or Backend, is to be able to find solutions when you run into problems or hickups.

Nobody can cover all those things, since they are very much individual problems. You can usually find other people that ran into the same or a similar problem by using search engines or something like stack overflow.

An experienced developer will be able to guess what the problem might be and attempt several things to fix it. This knowledge is not really teachable by following a course or youtube video. It's acquired through working with technologies and learning the ins and outs of those.