Massive, multimillion people gulag style camp system where people are forced to work on infrastructure projects for 10-15 year sentences (till they are too old

Massive, multimillion people gulag style camp system where people are forced to work on infrastructure projects for 10-15 year sentences (till they are too old to be a threat anymore), for yes things like petty theft. And yes this system must be built with an explicit goal to make a profit and have no outside funding. If it makes no profit, simplify security (less fancy cameras, guard shifts etc and more bullets). Eradicate the motivation for behaviour like that - make sure people know that stealing stuff from cars results in a multiple year incarceration with hard work and a bullet for minimal disobeyance (and probably, because we all know nearly none of these people can get fixed, with a goal of destroying their health and physical abilities to the point they really won't be a threat once released).