Senior Customer Service Representative

Ready to redefine what's possible in molecular diagnostics?

Join a team of brilliant, passionate innovators who wake up every day determined to transform healthcare. At BillionToOne, we've built something extraordinary—a culture where transparency fuels trust, collaboration drives breakthroughs, and every voice matters in our mission to make life-changing diagnostics accessible to all. We don't just aim for incremental improvements; we strive to build products that are 10x better than anything that exists today. Our people are our greatest asset: talented scientists, engineers, sales professionals, and visionaries 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—every innovation you contribute helps remove fear of unknown from some of life's most critical medical moments. If you're driven by purpose, energized by innovation, and ready to help build the future of precision medicine, this is where you belong.

We are looking for a Senior Customer Service Representative to provide exceptional service and support to BillionToOne's customers. This position holds a pivotal role in the organization and will act as the face of BillionToOne for our customers, including physicians, OB/GYN clinics, auxiliary staff, and patients. The ideal candidate for this role is an ambitious and intelligent individual who is highly self-motivated and who can effortlessly help drive and influence a positive patient and customer experience. TheSenior Customer Service Representative is an onsite position, located in our brand new, state-of-the-art, 90,000 square foot facility in Union City, CA.

Working hours are Monday-Friday, 8:30 AM to 5:00 PM PT.

Responsibilities:

Act as the subject matter expert on all BillionToOne prenatal products, services, processes, and systems; provide guidance to both internal teams and external customers.

Lead and mentor a team of Customer Service Representatives; provide training, real-time support, and ongoing performance feedback.

Manage and resolve complex or escalated inquiries from physicians, patients, and internal stakeholders with professionalism and confidence.

Analyze customer interactions and team performance to identify trends, improve workflows, and inform strategic decisions.

Partner cross-functionally with lab operations, commercial, and product teams to ensure client feedback informs broader organizational improvements.

Maintain high standards of documentation and data accuracy in CRM (Salesforce/Zendesk) and LIMS systems.

Take ownership of VIP accounts and high-priority client relationships to ensure white-glove service.

Represent the Client Services team in cross-departmental meetings and help implement best practices across the organization.

Drive initiatives to enhance customer experience, internal tools, and service delivery.

Serve as a cultural ambassador, embodying BillionToOne's values and helping shape a world-class Client Services organization.

Requirements:

2+ years of prior client-facing experience (diagnostic laboratory setting is a plus)

1+ years of team leadership or supervisory experience

4-year college degree (or equivalent in experience)

Experience with CRM tools (Salesforce, Zendesk, etc.) is a plus

Advanced organizational skills with the ability to handle multiple assignments

Ability to work in a very fast-paced, demanding environment

Outstanding verbal, written, and presentation skills - ability to effectively tailor messages to different audiences

Passion for creating a delightful experience for internal and external customers

Ability to analyze complex situations independently and implement appropriate solutions

Bilingual/Fluency in Spanish (preferred)

Benefits And Perks:

Working with a team of ‘superstars’ who bring out the best in everyone

An open, transparent culture that includes weekly Town Hall meetings

The ability to indirectly or directly change the lives of hundreds of thousands of patients

Free daily on-site lunches provided by top eateries

Latest and greatest hardware (laptop, lab equipment, facilities)

A variety of perks on campus (state-of-the-art gym, fully-stocked cafeteria)

Free on-site EV charging (compatible with all EVs, including Tesla)

At BillionToOne, we are proud to offer a combination of (1) competitive base pay, (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 up to $99,805 per year, including a base pay range of $78,030 to $83,232 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.

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About BillionToOne

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's already transformed the lives of over 500,000 patients worldwide.

Our Impact: We've pioneered game-changing diagnostic solutions that are redefining industry standards. Unity Complete™ stands as the only non-invasive prenatal screen capable of assessing fetal risk for both common recessive conditions and aneuploidies from a single maternal blood sample. In oncology, 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 $125 million in Annual Recurring Revenue in just four years. We've raised close to $400 million in funding, including a $130 million Series D round in June 2024, achieving a valuation of over $1 billion. This backing comes from world-class investors including Hummingbird, Adams Street Partners, Neuberger Berman, Baillie Gifford, and Premji Invest.

Our Recognition: Forbes recently named us one of America's Best Startup Employers for 2025, and we were awarded Great Place to Work certification in 2024—with an incredible 100% of our people reporting they are willing to give extra to get the job done. These honors recognize not just our innovation but the exceptional culture we've cultivated—one that remains authentically collaborative and transparent even as we've scaled.

Our Future: Headquartered in Menlo Park with facilities in Union City, California, we're continuing to push the boundaries of what's possible in molecular diagnostics. Recent clinical outcomes data for Unity Fetal Risk Screen and new advances in cancer diagnostics prove we're just getting started.

At BillionToOne, you'll join a diverse team of passionate innovators who believe that the best science happens when brilliant minds collaborate openly, think boldly, and never lose sight of the patients whose lives depend on our work.

Ready to help us change the world, one diagnosis at a time?

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