Senior AI Engineer I

Billiontoone; Edison (CA); On-site; USD 192,932 - 214,369; Full time

Benefits offered by this job

Multiple medical benefit options

Generous Family Bonding Leave

Retirement savings program with company match

Daily on-site lunches

State of the art gym

Job summary

BillionToOne in Menlo Park is seeking a Senior AI Engineer I to support AI solutions in healthcare. This role blends software engineering with strategic collaboration across teams. Responsibilities include deploying LLM applications, enhancing operational efficiency, and developing metrics for success.

Candidates should have 5+ years in software engineering or ML, proficiency in Python, and experience with LLM APIs. Join us to redefine diagnostics in a supportive, hybrid environment.

Qualifications

• 5+ years of experience in software engineering, data science, or ML engineering.
• Hands-on experience building applications with LLM APIs.
• Strong Python proficiency and comfort with SQL.

Responsibilities

• Build and deploy LLM-powered applications that integrate with internal systems and data sources.
• Partner with business stakeholders to identify automation opportunities.
• Own projects end-to-end: from prototyping to production deployment.

Skills

Experience in software engineering

Building applications with LLM APIs

Python proficiency

Comfort with SQL and relational databases

Experience deploying production systems

Familiarity with AWS

Excellent communication skills

Education

5+ years of experience

Tools

LLM APIs (OpenAI, Anthropic, etc.)

scikit-learn

PyTorch

TensorFlow

Job description

A Rare Opportunity to Shape the Future of Genomics

Join a team of brilliant, passionate innovators determined to transform healthcare. At BillionToOne, we've built a category-defining, publicly traded company on Nasdaq where transparency fuels trust, collaboration drives breakthroughs, and every contribution moves the needle on our mission to make life-changing diagnostics accessible to all. We don't just aim for incremental improvements; we build products that are 10x better than anything that exists today.

Our scientists, engineers, sales executives, and visionaries are united by an unwavering commitment to changing the standard of care in prenatal and cancer diagnostics. This is where cutting-edge science meets human compassion, and every innovation you contribute helps remove the fear of the unknown from some of life's most critical medical moments.

If you're driven by purpose, energized by innovation, and ready to help shape the future of precision medicine at scale, this is where you belong.

We are builders at heart. We value a strong sense of ownership, intellectual curiosity, and a bias toward action.

This is a hybrid role requiring 2-3 days per week on-site in Menlo Park with the team.

As BillionToOne scales rapidly, we are building a world-class Commercial Data & Applied AI team. We are currently seeking a highly motivated Senior AI Engineer I to support the design and implementation of AI and automation solutions that optimize operations across our commercial, billing, and customer experience teams.

This is a full-time senior role for engineers excited about applying LLMs, AI, and automation to real-world business challenges in healthcare. You will have the opportunity to join a new team and help shape the vision and culture. You will collaborate cross-functionally with stakeholders in Sales, Marketing, Revenue Operations, Billing, Customer Experience, and IT to identify high-impact opportunities for AI-driven solutions that improve scalability and efficiency.

Responsibilities

• Build and deploy LLM-powered applications (retrieval systems, AI agents, workflow automation, vector storage) that integrate with internal systems and data sources
• Partner with business stakeholders to identify automation opportunities, scope requirements, and define success metrics
• Build lightweight data pipelines and analytics to support AI applications and measure its impact
• Own projects end-to-end: from prototyping and iteration through production deployment and monitoring
• Establish best practices for prompt engineering, evaluation, and responsible AI use as the team scales
• Develop and lead internal training sessions on LLM fundamentals, prompt engineering, and AI-assisted development tools

Qualifications

• 5+ years of experience in software engineering, data science, or ML engineering
• Hands-on experience building applications with LLM APIs (OpenAI, Anthropic, etc.)
• Strong Python proficiency and comfort with SQL and relational databases
• Experience deploying and maintaining production systems
• Familiarity with AWS
• Excellent communication skills and ability to translate business problems into technical solutions
• Self-directed and comfortable with ambiguity in a 0-1 environment

Nice-To-Haves

• Previous entrepreneurial experience
• Experience with retrieval architectures, vector databases, and embedding models
• Familiarity with agent frameworks or workflow orchestration tools
• Experience with traditional ML frameworks (scikit-learn, PyTorch, TensorFlow)
• Prior work in healthcare, biotech, or other regulated industries

Benefits And Perks

• Working alongside brilliant, kind, passionate and dedicated colleagues, in an empowering environment, toward a global vision, striving for a future in which transformative molecular diagnostics can help millions of patients
• Open, transparent culture that includes weekly Town Hall meetings
• The ability to indirectly or directly change the lives of hundreds of thousands patients
• Multiple medical benefit options; employee premiums paid 100% of select plans, dependents covered up to 80%
• Extremely generous Family Bonding Leave for eligible employees (16 weeks, paid at 100%)
• Supplemental fertility benefits coverage
• Retirement savings program including a 4% Company match
• Increase paid time off with increased tenure
• Latest and greatest hardware (laptop, lab equipment, facilities)
• Daily on-site lunches provided from top eateries
• A variety of perks on campus (state of the art gym, restaurant)
• Free on-site EV charging (compatible with all EVs, including Tesla)

For this position, we offer a total compensation package of $300,806 per year, including a base pay range of $192,932 - $214,369 per year.

BillionToOne is an equal opportunity employer. We do not discriminate on the basis of race, religion, color, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status.

For more information about how we protect your information, we encourage you to review our Privacy Policy.

Our Impact

Unity Complete is the only non-invasive prenatal screen capable of assessing fetal risk for both common recessive conditions and aneuploidies from a single maternal blood sample. Unity Confirm enables non-invasive confirmation for high-risk screening results through the capture of intact circulating fetal cells using BillionToOne’s Fetal Cell Capture Technology. Our Northstar liquid biopsy test uniquely combines treatment selection with real-time monitoring, giving oncologists unprecedented precision in cancer care.

Our Growth

From $0 to $400M+ annualized revenue run-rate in just 6 years. In 2025, we completed one of the most successful IPOs for a medical diagnostics company, building on nearly $400M in private funding, including our $130M Series D in 2024 and backed by world-class investors including Hummingbird, Adams Street Partners, Neuberger Berman, Baillie Gifford, and Premji Invest.

Our Recognition

Forbes named us one of America's Best Startup Employers for 2025 and we're Great Place to Work certified, with 100% of our people willing to go the extra mile, even as we've scaled to over 700 employees.

Our Future

Headquartered in Menlo Park with facilities in Union City, CA, and a new lab opening in Austin, TX in 2027, we're continuing to push the boundaries of what's possible in molecular diagnostics. We're just getting started.

Ready to help us change the world, one molecule at a time? Learn more at billiontoone.com