Senior / Staff Power Electronics Engineer

About the Company Until is a moonshot company building a “pause button” for biology. Our near-term focus is organ-scale reversible cryopreservation: preserving donated organs at subzero temperatures without ice formation, then rewarming them uniformly for transplant. By solving this grand challenge, we’re laying the foundation for whole-body reversible cryopreservation, giving patients a bridge to future cures.

To achieve our goal, we are assembling an interdisciplinary team to develop perfusion systems, cryoprotectant formulations, and vitrification and rewarming hardware. We envision a future where no transplantable organ is lost to logistics, and no terminal diagnosis is final because patients can safely wait for future medicine to arrive.

About the Role

One of the key unsolved challenges in cryopreservation is the rewarming problem: how do we rapidly and uniformly rewarm whole organs and, ultimately, whole bodies to restart cryopreserved biology? Solving this requires MHz-frequency energy delivery into complex biological loads, involving high-voltage resonant power conversion, very high circulating currents, demanding insulation and safety constraints, and RF behavior that pushes well beyond conventional power electronics design.

We are building an elite team of electrical engineers and physicists with high autonomy, strong first-principles thinking, and a desire to build technology that feels impossible until it works. This role is for someone who can own the architecture of extreme power electronics hardware from first principles, as comfortable deriving a back-of-the-envelope model from circuit laws, electromagnetics, and thermal physics as they are running simulation tools and wiring up hardware in the lab.