Electrical Engineer / Applied Physicist

Until; San Francisco (CA); On-site; USD 150,000 - 200,000; Full time

Benefits offered by this job

Medical insurance

Dental insurance

Vision insurance

Flexible time off

Equity

401(k)

FSA and commuter benefits

Lunch and dinners

Learning stipend

On-site fitness center

Team social budget

Job summary

Until in San Francisco is seeking fast-moving, hands-on engineers and physicists to tackle the rewarming hardware challenge. You will design, build, test, and debug electrical hardware for organ rewarming systems, delivering high-power performance from first principles.

This role requires strong circuit theory, electromagnetics, and thermal physics intuition, plus experience wiring up real analog and digital circuitry, and developing power converters, instrumentation, and control software.

Qualifications

• Strong fundamentals in circuit theory, electromagnetics, and thermal physics.
• Experience designing and debugging real analog/digital circuitry.
• Background in instrumentation, data analysis, and lab bring-up.

Responsibilities

• 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 to model behavior and debug hardware issues.
• Build test fixtures, data acquisition, experimental setups, and control software.
• Learn quickly, own ambiguous problems, and contribute across the full hardware stack.

Skills

Circuit theory

Electromagnetics

Heat transfer

Data analysis

Control systems

Hands-on hardware

Education

BS/MS in EE or Physics

Tools

Data acquisition systems

Test fixtures

Control software

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.

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.