---
title: 'Senior / Staff Power Electronics Engineer at Until'
canonical: 'https://feeny.ai/job/senior-staff-power-electronics-engineer-until-bay-area-5y9bjz922v89'
type: 'job'
last_seen: '2026-09-14'
---

# Senior / Staff Power Electronics Engineer at Until

- **Company:** Until
- **Location:** Bay Area
- **Compensation:** $175k–$230k
- **Employment:** full-time
- **Work type:** onsite
- **Posted:** 2026-09-08
- **Last confirmed live:** 2026-09-14
- **Apply:** https://jobs.lever.co/until/08594f3f-0589-43c6-aad8-675e51da51b9

## Job description

## 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.

What You'd Do:

- Fully own power electronics hardware development for rewarming systems with unprecedented performance, from architecture through modeling, prototyping, validation, and iteration.

- Architect novel power converter topologies, high-Q resonant networks, impedance matching systems, and electromagnetic structures

- Drive system-level tradeoff studies across topology, frequency, voltage, current, insulation, thermal management, manufacturability, and safety.

- Roll up your sleeves in the lab to prototype, test, and debug hardware and instrumentation setups methodically using rigorous engineering best practices

- Design, build, and safely operate advanced laboratory infrastructure for validating high-voltage, high-current, MHz-frequency systems.

- Collaborate closely with engineers, scientists, physicists, and cryobiologists to design and validate whole-organ and whole-body rewarming systems.

About You:

- Deep understanding of power electronics, electromagnetics, and analog circuit design, both first-principles theory and practical design.

- 7+ years of hands-on experience (or equivalent advanced degree + track record) designing, building, and validating high-reliability, high-energy power systems.

- Proven experience with high-frequency, high-voltage power converter design, including device-level modeling, semiconductor selection (SiC/GaN), layout parasitic mitigation, impedance matching, shielding, and EMI/EMC.

- Strong lab skills with high-voltage, high-current, and high-bandwidth instrumentation; experience safely bringing up and debugging high-energy systems.

- Proficiency with simulation tools (e.g., SPICE, PSIM, ANSYS Maxwell) to model power electronic, electromagnetic, and thermal behavior before fabrication.

- Track record of exceptional engineering and a high degree of autonomy across the full hardware stack.

- Desire to join a small, fast-paced team on an excellent adventure.

Preferred Quailifications:

- Experience developing first-of-its-kind high-energy hardware: RF power delivery and impedance matching for plasma processing, RF generators, EV power converters, induction heating, pulsed-power systems or similar.

- Experience with medium-to-high voltage isolation systems, including creepage/clearance, dielectric materials, partial discharge mitigation, breakdown testing, and arc-flash safety.

- Experience designing high-Q resonant tanks, matching networks, RF generators, or high-power MHz-frequency systems.

- Experience with thermal design, liquid cooling, calorimetry, and multi-physics tradeoffs in high-power systems.

- Experience leading or mentoring highly technical, multidisciplinary engineering teams.

Benefits: Generous medical, dental and vision insurance coverage Flexible time off and paid holidays Competitive compensation package, including salary and equity Access to a 401(k) retirement savings plan FSA and commuter benefits Daily lunch and dinners, plus a variety of snacks Monthly learning stipend On-site fitness center Quarterly team social budget

## About Until

## Company Overview
- **One-liner**: Until is building reversible cryopreservation technology to bank whole human organs, extending viability from hours to weeks or months, with the long-term goal of whole-body cryopreservation.
- **Entity Type**: Private (Privately Held)
- **Headquarters**: San Francisco, California, United States
- **Founded**: 2025
- **Founders**: Laura Deming (CEO, Co-founder) and Hunter Davis Ozawa (CSO, Co-founder)

## Core Business
- Primary industry/industries: Biotechnology Research, Cryopreservation, Organ Preservation, Hibernation Science
- Target customers: Organ procurement organizations, transplant hospitals, and ultimately patients waiting for organ transplants (B2B with healthcare institutions)
- Mission or purpose statement: "Pressing pause on biological time, for those who need it most." The company aims to solve the organ procurement and matching problem by making donated organs last long enough to reach any patient in need.

## Products & Services
- **Reversible Cryopreservation for Whole Organs**: A technology that cools organs to -130°C using biocompatible cryoprotectants, then rewarms them without damage, turning hours of viability into weeks or months.
- **Cryoprotectant Discovery Engine**: A platform combining physics simulations and machine learning to screen over 250,000 candidate molecules for cryoprotective formulations that stay within a "Biocompatibility Budget" – preventing ice formation without harming cells.
- **Hibernation Research**: Exploratory work on inducing reversible metabolic arrest (hibernation-like states) in organisms, with potential applications in organ preservation and future whole-body suspension.

## Market Standing
- **Valuation/Market Cap**: Not publicly available (private company, founded 2025)
- **Key Metric**: Total Funding – Not disclosed; headcount of 53 employees (as of early 2026) with 9.5% monthly growth and 29 active job postings.
- **Notable Investors/Partners**: Not publicly listed. The company is co-founded by Laura Deming, a noted longevity and biotech investor (founder of the Longevity Fund), which may signal strong investor connections.
- **Growth Signals**: Rapid hiring (29 open roles for a 53-person team, +31.8% quarterly job posting growth), high-throughput screening scale (2,903 formulations tested in Q2 2026 alone), and public progress on cryoprotectant discovery.

## Competitive Advantages
- **Combination of Physics Simulation and ML**: Their discovery engine screens millions of molecules in silico before wet-lab validation, dramatically accelerating cryoprotectant development.
- **Biocompatibility Budget Framework**: A novel approach that distributes cryoprotectant toxicity across multiple mechanisms, avoiding the single-dose toxicity that has stymied the field for 50 years.
- **Focus on Whole Organs (not just cells)**: Extending cryopreservation from small samples (IVF, stem cells) to whole human organs – a much harder problem with massive clinical impact.
- **Talent Philosophy**: "Proof of work" culture that hires for demonstrated ability over credentials, with fast promotion for those who earn it.

## Strategic Focus
- **Immediate**: Scale up cryoprotectant discovery and validation to achieve reversible cryopreservation of a whole human organ (likely a kidney or heart) within the next few years.
- **Medium-term**: De-risk and build the foundation for whole-body reversible cryopreservation, enabling "a bridge to future cures" for patients with currently incurable conditions.
- **Talent Acquisition**: Aggressively hiring scientists, engineers, and operations staff across physics, biology, chemistry, and engineering disciplines to accelerate R&D.

## Why Work Here
- **Work Environment**: On-site in San Francisco (HQ). The work spans "the edge of physics, biology, and engineering" – from quantum-level simulations to handling real organs. Culture emphasizes "hard problems", rigor, and speed.
- **Culture**: Flat hierarchy, promotion on merit, "proof of work" over credentials. Team includes people from top universities and self-taught scientists alike.
- **Benefits**: Comprehensive medical/dental/vision, 401(k) via Guideline, unlimited PTO, paid parental and disability leave, on-site fitness center, catered lunch and dinner, plus snacks.
- **Engineering & Science**: Opportunity to work on cutting-edge cryobiology, nanotech, polymer chemistry, and high-throughput automation. The company uses AI tools in hiring but makes final human decisions.

## Sources
1. [untillabs.com/careers](https://www.untillabs.com/careers)
2. [untillabs.com](https://untillabs.com/)
3. [untillabs.com/our-team](https://www.untillabs.com/our-team)
4. [builtin.com/company/until-labs](https://builtin.com/company/until-labs)
5. [jobs.lever.co/until](https://jobs.lever.co/until)

## Other roles at Until

- [Electrical Engineer / Applied Physicist](https://feeny.ai/job/electrical-engineer-applied-physicist-until-bay-area-kgcsag1hxzzk) — Bay Area
- [Mechanical Engineering, Design](https://feeny.ai/job/mechanical-engineering-design-until-bay-area-cbaa9hk1my9k) — Bay Area
- [Senior Scientist, Cardiac Preservation (Organ Perfusion)](https://feeny.ai/job/senior-scientist-cardiac-preservation-organ-perfusion-until-bay-area-b452rfthhqkp) — Bay Area
- [Research Associate (Organ Perfusion)](https://feeny.ai/job/research-associate-organ-perfusion-until-bay-area-0b1srem75ztf) — Bay Area
- [Research Assistant, Materials Chemistry (Nanoparticles)](https://feeny.ai/job/research-assistant-materials-chemistry-nanoparticles-until-bay-area-3m7hw2phjy84) — Bay Area
- [Scientist/ Senior Scientist - Translational Cardiac Biology](https://feeny.ai/job/scientist-senior-scientist-translational-cardiac-biology-until-bay-area-4t7rwnr11n7h) — Bay Area
- [Head of Legal](https://feeny.ai/job/head-of-legal-until-bay-area-a15h6wha3f21) — Bay Area
- [Research Associate, Hibernation](https://feeny.ai/job/research-associate-hibernation-until-bay-area-a9jr1rkbe83f) — Bay Area
- [Physics and Engineering Technician](https://feeny.ai/job/physics-and-engineering-technician-until-bay-area-csevrzjywfzk) — Bay Area
- [Sr. Mechanical Engineer, Fluidics/Perfusion](https://feeny.ai/job/sr-mechanical-engineer-fluidics-perfusion-until-bay-area-fkstk4p7d9q0) — Bay Area