In the race to build the physical infrastructure of artificial intelligence, two companies — Applied Digital and IREN — are staking out divergent paths through the same uncertain terrain. Applied Digital has grown with striking speed, tripling its revenue in a single year by leasing high-performance computing facilities, while IREN is dismantling its crypto-mining past to reinvent itself as an AI cloud provider with contracts from Microsoft and NVIDIA. Both are spending billions before they earn billions, and the choice between them is less a question of which is better and more a question of