As per my knowledge, I have divided SharePoint Developers into three categories. Each of them in three groups knows SharePoint very well.
Managing complex custom list and creating custom workflows are both come under Application maintenance. As per the knowledge on custom application development I have assumed the developers into three groups,
End User SharePoint Developer: End user SharePoint developer can have owner or contributor permissions on a site. He can able to create or modify list views (personal or Shared). He is able to change the complex list view to his needs by filtering and sorting the list data. User can add web parts and change the settings of the web part if he has owner permissions to page.
End User SharePoint Developer can use Internet explorer or any other web browsers.
This user mainly uses Internet Explorer and SharePoint designer to build the applications.
Advanced SharePoint Developer: Advanced SharePoint Developer will have knowledge on SharePoint out of Box features, SharePoint Designer and Custom development using Visual Studio. He can able to build features, Solutions and workflows using Visual Studio. He will have command on everything in SharePoint as well as .net concepts.
This user uses Internet explorer, SharePoint designer and Visual Studio to do his work.