Here is what happened to the common, low ranking German soldiers after they lost WW2

It depends on who captured them. In the West, after screening, many were released relatively quickly in 1945–1946.

This was not mercy. It was expensive to keep prisoners and what was left of Germany, badly needed manpower; very quickly. Western Germany, besides being wrecked, needed workers very badly. Obviously, the war had taken a very heavy toll on the German workforce.

In addition, millions of weary, hungry and traumatized ethnic Germans were dumped(Eastern Expulsions), with nothing but the clothes they were wearing, within German boundaries. Most of these were women, children or the elderly(those that could keep up). These millions had to be housed and fed too.

Starvation was a very serious threat and that is not an exaggeration. Germany needed food and fuel to survive the winter. German miners and farmers needed to get back to work and be more productive than they had ever been to avoid famine and death from cold. The logistical system needed to be repaired so Germany could survive at a minimal level.

In the East, many soldiers were kept as slave labor, some into the mid 1950s. The Soviets had lost so much manpower, they needed labor in every sector of the economy. Under brutal conditions, German prisoners were used as slave labor to produce everything. As far as the Soviets were concerned, that was the absolute LEAST the Germans could do after what they had done.

Indeed, it is counter intuitive, but Stalin wanted as many German prisoners as possible; he needed the labor. The East had been wrecked by the war too.

In the West, German prisoners, many very young, were assigned unpleasant tasks such as removal of explosives, mines, etc.:

For the Western Allies, the issue was how many prisoners to allocate to keeping Germany alive and how many to devote to nasty tasks such as mine clearance.

you can click here to watch the video