Electrical Engineer / Applied Physicist

Until; San Francisco (CA); On-site; USD 140,000 - 190,000; Full time

Benefits offered by this job

Medical, dental, vision

Flexible time off

Salary and equity

401(k) retirement plan

Commuter benefits

Daily meals

Job summary

Until seeks fast-moving engineers and physicists to develop first‑of‑its‑kind electrical systems for organ rewarming. You’ll design and test high‑power hardware, power converters, and control software, using circuit theory, electromagnetics, and thermal physics to explain and optimize behavior.

A BS/MS in EE or Physics is required, with hands‑on lab experience. You will work in a small, fast‑paced team tackling challenging biology‑tech problems, from schematic to bench bring‑up, with ownership

Qualifications

• Strong command of circuit theory, impedance and energy storage, plus physics fundamentals.
• Experience designing analog and digital circuitry from schematic to bench.
• Ability to model systems from first principles using data and measurements.
• Hands-on hardware development with instrumentation and test fixtures.
• Background in control systems, instrumentation, and data analysis.

Responsibilities

• Design, build, test, and debug electrical hardware for organ rewarming systems.
• Develop power converters, resonant networks, instrumentation and control software.
• Model system behavior from circuit theory, electromagnetics, and thermal physics.
• Create test fixtures, data acquisition setups, and hardware bring-up routines.
• Learn quickly, own ambiguous problems, and contribute across hardware stack.

Skills

Circuit theory

Electromagnetics

Heat transfer

Analog circuits

Digital circuits

Instrumentation

Data analysis

Control systems

Hands-on hardware

Education

BS/MS in EE or Physics

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? One of the key ingredients is building first-of-its-kind electrical systems for delivering high power into complex biological loads.

We are looking for fast-moving, hands‑on engineers and physicists with strong fundamentals, high autonomy, and a desire to build technology that feels impossible until it works. This role is for someone who is as comfortable deriving a back‑of‑the‑envelope model from circuit laws, electromagnetics, and thermal physics as they are wiring up hardware in the lab.

What You'd Do:

• Design, build, test, and debug electrical hardware for organ rewarming systems.
• Develop power converters, resonant matching networks, instrumentation, and control systems.
• Reason from first principles, using circuit theory, electromagnetics, thermal physics and measurement data, to model system behavior and debug ambiguous hardware problems
• Build test fixtures, data acquisition systems, experimental setups, and control software for high‑power hardware validation.
• Learn quickly, take ownership of ambiguous problems, and contribute across the full rewarming hardware stack.

About You:

• You have a strong command of circuit theory and physics (impedance, resonance, energy storage, electromagnetics, and heat transfer), and you reach for these instinctively when a piece of hardware isn’t behaving as expected
• You have a project you can walk us through in depth: not just what you built, but the physics and math reasoning that got you there, and where your first mental model was wrong
• You can make order‑of‑magnitude estimates quickly, and you can explain the physical intuition behind them clearly to someone else
• You’ve designed, built, and debugged real analog and digital circuitry, taking systems from schematic to bench and through bring‑up
• You have experience with basic control systems, instrumentation, data analysis, and hands‑on experimental hardware
• You have a BS/MS in EE, Physics, or equivalent self‑taught depth; we care more about demonstrated reasoning ability than credentials.
• You want to join a small, fast‑paced team on an excellent adventure.

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

We may use artificial intelligence (AI) tools to support parts of the hiring process, such as reviewing applications, analyzing resumes, or assessing responses and identifying potential inconsistencies or verification signals in application materials based on available information. These tools assist our recruitment team but do not replace human judgment. Final hiring decisions are ultimately made by humans. If you would like more information about how your data is processed, please contact us.