Sr. Software Engineer

Job Description

Job Description

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 time-critical challenge, we’re laying the foundation for medical hibernation : pausing molecular motion to give patients a bridge to future cures.

To achieve our goal, we are assembling an interdisciplinary team to develop perfusion systems, cryoprotectant formulations, controlled-rate freezers, and vitrification and rewarming protocols for human tissue. We are also building out our medical hibernation team to tackle the challenges of whole-body cryopreservation, beginning with rodent models.

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

As a Senior Software Engineer at Until, you’ll develop the computational and infrastructure backbone that enables our science to move faster. You'll build cloud infrastructure, design database schemas, and develop internal tooling that forms the foundation of our internal scientific data platform. You will own projects end-to-end, collaborate across disciplines, and set a high bar for developing code that scales with the team.

About You

• Degree in Computer Science or a related field (Applied Mathematics, Statistics, Data Science)
• Strong understanding of computer science fundamentals, including algorithms, operating systems, concurrency, memory management, and networking.
• 3+ years of relevant professional experience developing modular, maintainable, and performant code in Python or a similar language.
• Prior experience with backend development using frameworks such as Flask, FastAPI, or Django.
• Experience working with relational databases such as PostgreSQL, including schema design and query optimization.
• Strong experience with cloud infrastructure (AWS, GCP), including Infrastructure as Code tools such as Terraform.
• Familiarity with cloud security best practices, including identity and access management and network security.
• Proficient with developer tooling, including Linux command line, Git, and shell scripting.
• Ability to think from first principles and tackle complex, cross-disciplinary problems with other scientists and engineers.
• Track record of owning software projects end-to-end.

While this represents our expected range based on market data, final compensation will be determined based on your specific qualifications and may be outside this range. Please keep in mind that the equity portion of the offer is not included in this estimate.

As an equal opportunity employer, Until is committed to providing employment opportunities to all individuals. All applicants for positions at Until will be treated without regard to race, color, ethnicity, religion, sex, gender, gender identity and expression, sexual orientation, national origin, disability, age, marital status, veteran status, pregnancy, or any other basis prohibited by applicable law.

We may use artificial intelligence (AI) tools to support parts of the hiring process, such as reviewing applications, analyzing resumes, or assessing responses. 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.