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.

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 seek a Process Engineering Associate II whose interests span molecular diagnostics, process optimization, and quantitative problem solving. In this role you will (1) drive process improvement and development to enhance clinical assay performance, (2) support technology transfer from R&D into our high-throughput CLIA lab, and (3) troubleshoot and identify root causes of recurring errors to enable long-term corrective actions. You will also play a key role in standing up our newly built lab in Austin, TX. You will leverage and deepen your expertise across molecular techniques, laboratory automation, and data analysis while contributing directly to category-defining NIPT assays that transform patient lives one molecule at a time. This onsite position starts at our Union City, CA laboratory and will relocate to Austin, TX in summer 2027. The Process Engineering Associate II reports to the Senior Development Scientist.

Responsibilities:

• Design, execute, and analyze wet lab experiments to improve process efficiency and assay reliability.
• Evaluate new molecular biology techniques and technologies to enhance assay performance.
• Perform complex manual and automated laboratory procedures (e.g. nucleic acid extraction, PCR, sequencing, reagent preparation).
• Conduct assay validation studies to qualify new and improved assays for clinical use at both sites.
• Build data analysis and software tools to monitor process health, surface sources of error, and accelerate troubleshooting.
• Collaborate with the team to analyze complex data, diagnose issues, and implement solutions.
• Support technology transfer to our new Austin, TX CLIA lab to bring the new site online.
• Present project progress, data, and technical insights to the team and department.

Qualifications:

• BS or MS in a relevant scientific or engineering discipline (e.g., Bioengineering, Chemical Engineering, Molecular Biology, Biochemistry, Chemistry, or Physics).
• At least 1 year of hands-on lab research experience, including core molecular biology techniques (e.g., PCR, DNA/RNA extraction, sequencing).
• Exceptional analytical reasoning and troubleshooting skills, with experience in data analysis (bioinformatics, statistical analysis, or similar) and comfort using modern AI tools.
• Strong mathematical and statistical aptitude, with a process- and systems-level mindset.
• Excellent attention to detail and clear written and verbal communication.
• Driven, creative, and persistent, with a willingness to go above and beyond and to work both independently and collaboratively in a fast-paced environment.
• Willingness to relocate from Union City, CA to Austin, TX in summer 2027.

Nice-to-haves:

• Start-up experience.
• Previous automation or clinical laboratory experience.
• Experience with next-generation sequencing (NGS) and library preparation.
• Experience in a cell-free DNA setting.
• Prior experience with technology transfer, assay validation, or new lab/site standup.

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%)
• Free UNITY Complete NIPT testing for employees & spouses
• 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)
• Free 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 $104,322 per year, including a base pay range of $75,029 - $85,748 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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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