Indeed, DPRK was doing just fine until USSR dissolved, and then they went through some bad times because of all the sanction. The main things they need are access to food and fuel, both of which Russia can supply them in effectively unlimited amount. Meanwhile, Russian economy is overheating now where there isn't enough labour available to sustain the growing industrial activity. This is where DPRK fits perfectly since they used to be a major manufacturing hub for USSR. I saw that they're now opening up a join economic development zone with Russia that looks very similar to that.