OSDev.org

When I cook shrimp I always have to pull out the little track that runs along their back, but when going to a restaurant and getting shrimp with the shell then pulling the shell off I never find this tract along it's back?

The digestive track along it's back.

How do they do it?

Maybe they genetically engineer those shrimp with no shells at all

From the explanation you're I assume you're talking about prawns .

I would assume that in the restaurants they have some method that allows them to remove the track without losing bits of it along the way. Possibly heating enough to cause enough of an expansion that it is movable?