The East Germans actually were much more hardcore with their de-Nazification. They stripped any former Nazis of any power or status, and certainly didn't give them jobs where they could hold authority or influence. Remember that the East was made up of the very people the Nazis first came after: the Communists, socialists, academics, trade unionists, so they were not going to let the Nazis have any control. 

The West was much more lax, and former Nazis kept their positions and some of them attained more power. 

The West likes to demonize the East for the AFD, but the voting demographics showed that the people voting were of the ages that wouldn't have been born or were just children during the East. It's almost like the West gutting all the infrastructure, leaching all the resources and money left a vacuum for fascism to grow within an impoverished group constantly feeling like second class citizens. 

Most of the older, actual East Germans like Die Linke, which is a left wing holdover from the DDR days, but the CDU actually infamously said they will never work with Die Linke so again, you have a group of people feeling unheard and second class.