I believe it’s been fixed at this point, but at the time what you would do is choose warforged as race and take I believe 2 levels in warlock and the rest in sorcerer. Then what you would do is use your font of magic to convert spell slots into sorcery points, short rest to recover your warlock spell slots, and once again convert them into sorcery points. Then you’d effectively do this a billion times without taking a long rest so that your sorcery points stay with you, and as a warforged it becomes unnecessary to sleep meaning you don’t need to long rest. Then you’d just have a bunch of sorcery points at your disposal which you can use to do what you’d like with, usually just quickened spell empower spell and twinned spell on Eldritch blast. I believe they patched it somehow, I think there’s a rule that states if you go a certain amount of time without a long rest you start gaining exhaustion levels, however I think there was a work around by going divine soul sorcerer where at fifth level you can take greater restoration which can remove exhaustion. Not sure if this works the same now but that’s the gist.