BillionToOne Logo

BillionToOne

Senior AI Engineer I

Reposted 11 Days Ago
Be an Early Applicant
Easy Apply
In-Office
Menlo Park, CA
174K-201K Annually
Senior level
Easy Apply
In-Office
Menlo Park, CA
174K-201K Annually
Senior level
Design, build, and deploy LLM-powered applications and automation for commercial, billing, and CX teams. Partner with stakeholders to scope solutions, create data pipelines, own end-to-end deployments and monitoring, establish prompt engineering and responsible AI practices, and run internal training.
The summary above was generated by AI
Ready to redefine what's possible in molecular diagnostics?

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.

With over 700 employees, half a million patients helped, and one of the most successful IPOs in medical diagnostics history behind us, we're just getting started. 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.

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.

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.

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 their 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-to-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 new parents (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)

At BillionToOne, we are proud to offer a combination of a (1) base pay range (actual amount offered is based on experience and salary/equity options split that the candidate chooses), (2) generous equity options offering, (3) corporate bonus program, on top of (4) industry leading company benefits (free healthcare options, 401k match, very generous fully paid parental leave, etc.).

For this position, we offer a total compensation package of $280,705 per year, including a base pay range of $174,241 - $200,641 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.

BillionToOne is a next-generation molecular diagnostics company on a mission to make powerful, accurate diagnostic tests accessible to everyone. Our revolutionary QCT molecular counting technology enhances disease detection resolution by over a thousandfold using cell-free DNA,a breakthrough that has already transformed the lives of over half a million patients worldwide.

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. 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 $150M+ in Annual Recurring Revenue in just five 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

Top Skills

Anthropic
AWS
Llm Apis
Openai
Python
Relational Databases
SQL

Similar Jobs

22 Days Ago
In-Office
200K-250K Annually
Mid level
200K-250K Annually
Mid level
Artificial Intelligence • Information Technology • Machine Learning • Natural Language Processing • Software
As a Senior Software Engineer, you'll scale and optimize a Generative AI product, enhance infrastructure, design APIs, and collaborate with teams to build robust solutions.
Top Skills: Api DesignCloud ComputingGenerative AiLoggingMachine LearningMetrics FrameworksProgramming Languages
22 Days Ago
In-Office
Senior level
Senior level
Artificial Intelligence • Information Technology • Machine Learning • Natural Language Processing • Software
As a Senior Software Engineer, you will enhance AI systems, implement algorithms, mentor engineers, and collaborate on complex engineering challenges.
Top Skills: GoJavaLlmsPython
22 Days Ago
In-Office
Senior level
Senior level
Artificial Intelligence • Information Technology • Machine Learning • Natural Language Processing • Software
The role involves designing and enhancing AI agent systems, implementing AI algorithms at scale, programming in Python, Golang, and Java, and mentoring other engineers.
Top Skills: GoJavaLlmsMachine LearningPython

What you need to know about the Los Angeles Tech Scene

Los Angeles is a global leader in entertainment, so it’s no surprise that many of the biggest players in streaming, digital media and game development call the city home. But the city boasts plenty of non-entertainment innovation as well, with tech companies spanning verticals like AI, fintech, e-commerce and biotech. With major universities like Caltech, UCLA, USC and the nearby UC Irvine, the city has a steady supply of top-flight tech and engineering talent — not counting the graduates flocking to Los Angeles from across the world to enjoy its beaches, culture and year-round temperate climate.

Key Facts About Los Angeles Tech

  • Number of Tech Workers: 375,800; 5.5% of overall workforce (2024 CompTIA survey)
  • Major Tech Employers: Snap, Netflix, SpaceX, Disney, Google
  • Key Industries: Artificial intelligence, adtech, media, software, game development
  • Funding Landscape: $11.6 billion in venture capital funding in 2024 (Pitchbook)
  • Notable Investors: Strong Ventures, Fifth Wall, Upfront Ventures, Mucker Capital, Kittyhawk Ventures
  • Research Centers and Universities: California Institute of Technology, UCLA, University of Southern California, UC Irvine, Pepperdine, California Institute for Immunology and Immunotherapy, Center for Quantum Science and Engineering

Sign up now Access later

Create Free Account

Please log in or sign up to report this job.

Create Free Account