In the rapidly evolving landscape of electric vehicles (EVs), the shift towards 800V power system architectures is gaining serious momentum. Our white paper “HIL Simulation’s Crucial Role in the 800V EV Transition” explores the reasons behind the move to 800V, the varied challenges this move presents to test professionals, and the pivotal role hardware-in-the-loop (HIL) simulation is playing in the transition from 400V to 800V architectures. In addition, we detail how to efficiently create a HIL test platform and outline a detailed migration path for testing 800V architectures.