BillionToOne is a next-generation molecular diagnostics company dedicated to developing powerful and accurate diagnostic tests that are accessible to all. Our innovative QCT molecular counting technology significantly enhances the resolution of disease detection using cell-free DNA by over a thousandfold. This groundbreaking technology is integral to our product offerings, including one of our flagship products, Unity Complete™, the only non-invasive prenatal screen capable of assessing fetal risk for both common recessive conditions and aneuploidies from a single maternal blood sample. Leveraging the same molecular counting technology, we've expanded our impact into oncology in 2023 with a pioneering liquid biopsy test, Northstar, that combines treatment selection with monitoring. To date, over 500,000 patients have benefited from our innovative and precise diagnostic tests, and our Annual Recurring Revenue (ARR) has grown from $0 to $125 million in the last ~4 years.

BillionToOne has successfully raised close to $400 million in funding, with a notable $130 million Series D round completed in June 2024, resulting in a company valuation of over $1 billion. This funding has come from prestigious global institutional investors, including Hummingbird, Adams Street Partners, Neuberger Berman, Baillie Gifford, and Premji Invest. BillionToOne has recently been recognized by Forbes as one of America's Best Startup Employers for 2024, highlighting the company's exceptional work environment and commitment to innovation.

Our team has grown significantly and we now proudly employ over 400 highly skilled individuals. Despite substantial growth, we have successfully maintained the unique culture that has defined BillionToOne from inception, continuing to cultivate a team that is not only diverse and passionate but also innovative. Headquartered in Menlo Park, California, with an additional facility in Union City, California, BillionToOne remains at the forefront of significant advances in molecular diagnostics, evidenced by the recent announcement of clinical outcomes data for its Unity Fetal Risk Screen and new advancements in cancer diagnostics. For more detailed information about BillionToOne and its groundbreaking work, please visit our website at

We are looking for a Process Engineering Associate I/II to join our growing superstar Process Engineering team in support of clinical patient testing in our high throughput CLIA lab. The Process Engineer Associate is responsible for (1) developing new tools for improved clinical workflow efficiency, (2) working independently to troubleshoot instrumentation, and (3) identifying root causes of recurring errors with proper documentation to enable long term corrective actions. This role will enable an individual to gain both deep and broad experience in the areas of process engineering, data analysis, experimental design, and automation. This position will also allow time to apply knowledge of coding languages like python and R to real world problems encountered within high paces and dynamic clinical laboratories. This is considered an onsite role and will require the majority of days to be spent in the office (at Union City and Menlo Park).


  • Apply sound engineering practices to scale, optimize, and improve molecular biology methods
  • Develop methods to compile and analyze large amounts of process data to assess for process stability, trending, and areas for improvement
  • Develop and implement simple to medium complexity data and information handling tools to aid in efficient sample processing within the clinical laboratory 
    • Expected to require moderate proficiency in R or Python
  • Apply six sigma, Design-for-quality, and 5S frameworks to existing or new processes to improve both capability, scalability, and quality of molecular diagnostic assays
  • Support high throughput CLIA lab through troubleshooting instrumentation and re-qualifying instrumentation back into clinical use
  • Identify root causes for process and instrument errors and develop short term and long term solution
  • Develop effective training plans for clinical personnel on modified/improved workflows
  • Generate proper documentation for all troubleshooting and qualification


  • Bachelor’s degree or equivalent degree in biology or clinical related sciences
  • At least 6 months of experience with molecular biology techniques in a research or clinical laboratory
  • Excellent attention to detail
  • Effective written and verbal communication skills
  • Possess logical troubleshooting skills
  • Previous automation or clinical laboratory experience is preferred


  • Start-up experience
  • Knowledge of medical genetics
  • Experience in a cell-free DNA setting

Benefits And Perks:

  • Working with a team of ‘rockstars’ who bring out the best in everyone
  • Open, transparent culture that includes weekly Town Hall meetings
  • The ability to indirectly or directly change the lives of hundreds of thousand patients
  • Multiple medical benefit options; employee premiums paid 100% of select plans, dependents covered at 80%
  • Extremely generous Family Bonding Leave for new parents (16 weeks, paid at 100%)
  • Retirement savings program including a 4% Company match
  • Free daily on-site lunches provided from top eateries
  • Latest and greatest hardware (laptop, lab equipment, facilities)
  • 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, on top of (3) industry leading company benefits (free healthcare options, 401k match, very generous fully paid paternal leave etc.).

For this position, the base pay range is: $52,000-$75,000 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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