While there’s always more to say on the subject, as to your main question you might be interested in these previous answers:

• How quick of a process was the denazification of Germany after the end of WWII? by u/Abrytan
• In the 1950s, from where did the East and West German militaries draw their officer corps? with u/kieslowskifan
• What sort of treatment, professionally speaking, was given to German academics whose credentials were earned during the Nazi era? by u/kieslowskifan