I have done battle with roaches and while I don't think my issue was as bad as yours sounds, I have a strategy that has worked everywhere I've lived.

The first step is Advion. This is a very specific cockroach poison that is illegal in some states but I'm pretty sure you can get it in NJ. Full disclosure, be careful with this stuff. It will kill your pets if they eat it. Dab it everywhere a water or gas pipe comes into your apartment. So, the pipes under your sinks, your dishwasher, your toilet your radiators, everywhere you can reach. Also, put it in vents and on the back of electrical outlets (take the covers off, stick a bit on the gang box or back of the cover, put it back). Again, this stuff is not nice for pets so don't put it anywhere they can get it, and you don't need much, but it will cause colony collapse in cockroaches.

Next, get bait traps and stick them behind all your large appliances, on top of your kitchen cabinets and maybe a couple in closets if the problem is in the whole apartments.

Last, sprinkle diatomaceous earth in the back of all your cabinets and pantries, and in all the thresholds into your apartment (door jambs and window sills). This stuff is totally non toxic, some people take it as a supplement, but roaches do not like it and will avoid it. You can be as liberal as you want.

This has always worked for me even in buildings that have had problems. Takes about two weeks to fully clear up. You still might see one or two here and there, but for the most part they should be gone. Good luck.